I have created some class A.cs whose function is to be used in B.cs then B.cs is called in ASP.net webforms in codebehind. My files A.cs and B.cs is kept in App_Code folder.
The issue is if i call the function of B.cs in asp.net webform codebehind i get error that function is not defind are you missing an assembly? After researching on SO, i found to make class build action to compile. Though it solved the issue, but when i build the app i got error that my assembly is present in root as app_code and assembly.dll both
Then i reverted the process, and got same function not found issue.
I am seriously unable to figure out,How to solve this???
I run into this exact problem before. The way I fixed it is moving all the code files form App_Code folder to a Classes folder (or any folder of your choice) and then compile and fix the compiling errors. After, the error went away.
It sounds like you may have defined the Gal.DB.Service class in both the ASP.NET web app (under App_Code) and in an assembly that the web app references (i.e. Gal.DB.Manager.DLL).
The class can only be defined once.
try clearing the temporary asp.net files, depending on what web server you are using, you'll want to stop, reset or kill it to release the files before deleting them.
It sounds like this is a web app, where asp.net makes its best guess about what needs to be compiled. If this compilation model causes too much trouble, web project might be easier in the long run.
I am sorry if this is not really a coding question (it depends on if its my code causing the problem I suppose).
I have seen this question: Tracking down intermittent 'Object reference not set to an instance of an object.' error on build
However, it has not been of much help (although if you read the comments, you will see that I thought it did help for a while there).
When I try publish my website, occasionally, I will get an error with no file or line reference:
Pre-compiling Web Site
Building directory '/App_Code/'.
Building directory '/'.: Publication (web): Object reference not set to an instance of an object.
Pre-compilation Complete
------ Skipped Publish: Project X:\, Configuration: Debug Any CPU ------
I know the usual causes of "Object reference not set to an instance of an object" but this seems a bit different, isn't it supposed to be a runtime error? Not a build error?
What is weird is that it happens, seemingly at random (about 25%-33% of the time). I can try to publish it and have it fail. Then try again straight after, without changing anything and it works fine.
I started getting this error after moving some of my functions (VB.net btw) to a new file in the App_Code folder so they can be accessed by all pages of the site.
If you need any more info, please let me know.
Thanks,
EDIT: After further investigation, it seems to only happen if I try to publish the website within a few seconds of saving changes to any file within it. What could cause this?
The same error occurred for me to, I deleted the dlls of the custom controls in the web site that are already in the bin, then i published the web site, and succeeded
IF you have any custom/usercontrols in your project, they are actually running at design time and can give object ref errors. This can occur during builds too. In that case, a property is being referenced that is NOTHING and throws the error.
I had a similar problem with a Windows Form project.
Wherever I try to move a custom control on the windows form, and then try to save the form, VS2010 comes back with "Object not set to an instance of an object".
I suspected the error was deep down in the layers of abstraction in my inherited code, but couldn't work out how deep to go, without reviewing every line of code.
My solution to this problem is this.
Open up another instance of Visual Studio 2010
Menu: Debug | Attach to Process..
Search for "devenv.exe xxx YourApplicationName..." and select it
Click "Attach"
Menu: Debug | Exceptions..
Tick all the boxes in the thrown column, then "OK"
Your second instance of VS2010 is not debugging your first instance, including all the custom controls.
Return to the first instance of VS2010, and repeat the actions that caused the error in the first place, the second instance of VS2010 will break at the line of code that has the error.
You may want to look at this link there is a bug in vs2012
https://connect.microsoft.com/VisualStudio/feedback/details/749901/error-when-i-click-publish-object-reference-not-set-to-an-instance-of-an-object
I'm working on an MVC3 project and receive the following error:
Parser Error Message: Could not load type 'GodsCreationTaxidermy.MvcApplication'.
Source Error:
Line 1: <%# Application Codebehind="Global.asax.cs" Inherits="GodsCreationTaxidermy.Core.MvcApplication" Language="C#" %>
The error I get is cannot load GodsCreationTaxidermy.Core.MvcApplication but in this screen shot the Core part isn't displaying in the error:
Does anyone have any ideas or a solution to this error?
Check that the project output path (project properties / Build) is set to bin and not bin\Release or bin\Debug
For some reason IIS (VS development Server or Local IIS) always accesses the libraries from the bin directory (and won't look up for subdirectories)
Your local web server is running different code than what you're actually working on. Ensure you have stopped debugging, stop your local web server, clean and rebuild as Peter suggested, double-check your global.asax and global.asax.cs, and try again.
If this doesn't work and you are using local IIS, try removing the site in IIS Manager and recreating it manually.
Try modifying your global.asax file (simple add a space somewhere) and re-run. this will force the built in webserver to refresh and recompile the global.asax file.
Also do a clean and rebuild - should fix the problem
This happens sometimes if you change namespace information (project or class level) after the global.asax is generated.
Right click on the Global.asax file and select "Open With" and then select "XML (Text) Editor with Encoding" (other editors may work as well, but this is what I use).
Then edit the "Inherits" section in the XML directive
<%# Application Codebehind="Global.asax.cs" Inherits="GodsCreationTaxidermy.MvcApplication" Language="C#" %>)
so that it matches the actual full name of your Application class. And that's it.
Another option is to copy off all your code from Global.asax.cs and then delete and create another Global.asax file (and then copy the code back into Global.asax.cs).
I closed and reopened visual studio and it worked.
I had to go to BUILD -> CONFIGURATION MANAGER and -- ahem -- check the box next to my project to ensure it actually gets built.
I had this issue today, and it took me a while to find the cause.
Basically, my main VS2015 project was including a sub-project which had been built using a higher version of .Net Framework.
Bizarrely, when you have this problem, VS2015 will happily report that the solution has built okay, but when you try and run the website, it just gives you that misleading error, suggesting that your Global.asax.cs file is wrong.
So, if you see this error, and Cleaning/Rebuilding doesn't help, open your Project's References tree, and check for exclamation marks.
Also, check your Output window for messages like this:
The primary reference "C:\Projects\Business Objects 4\bin\Release\BusinessObjects.dll"
could not be resolved because it was built against
the ".NETFramework,Version=v4.5" framework.
This is a higher version than the currently targeted framework
".NETFramework,Version=v4.0".
The solution, of course, is to right-click on your main project, select the top tab, "Application", and change the Target Framework version to a higher version which matches your sub-project.
It's annoying that Visual Studio 2015 will let you fully build and run Solutions which quietly contain this problem. It's asking for trouble..!
"BUILD -> CONFIGURATION MANAGER and -- ahem -- check the box next to my project to ensure it actually gets built."
That and going to the project folder in windows explorer, pressing options and unchecking the "Read only" checkbox helped.
I just encountered this on an MVC5 application and nothing was working for me. This happened right after I had tried to do an SVN revert to an older version of the project.
I had to delete global.asax.cs and then added a new one by right clicking Project -> Add New Item -> Global.asax and THAT finally fixed it.
Just thought it might help someone.
I was working on an older 'folder based' ASP.NET web project (which I loathe) - and found this to be my fix:
Create an App_Code folder (if you didn't have one already)
Move the Global.asax.vb file into the App_Code folder
The markup in Global.asax can leave out any namespaces (at least, for this style of project, afaik):
<%# Application Codebehind="Global.asax.vb" Inherits="MyApp" Language="VB" %>
...where "MyApp" is the name of the class being defined in Global.asax.vb
Delete the .vs directory from the solution root. Clean. Rebuild.
This issue drives me bonkers once in awhile and I inevitably end up here paging through answers. I suspect there are multiple causes that can produce this exception, this once works for me.
You can also check your site's properties in IIS. (In IIS, right-click the site and choose Properties.) Make sure the Physical Path setting is pointing to the correct path for your application not some other application. (That fixed this error for me.)
Empty the bin folder. Build all the dependent class libraries and refer them in the main project, and build the complete solution.
Source
I have to report that I tried at least 4 suggestions from this post. None of them worked. Yet I am happy to report that I recovered by retrieving from back up. Only had to update my last code changes from log file. Took less then 10 minutes. Spent 3 times that reading this post and trying other suggestions. Sorry.
It was a very weird error. Good luck to anyone else encountering this gremlin.
I have same problem when I have 2 instance of Visual Studio running same project. So I closed both Visual Studio and opened only one instance and It works fine now!
This issue I was solved by giving right permission of the folder as well as check from IIS.
I was given permission to everyone as I am testing in my local environment. But in publish mode I think we give only permission to ASP.Net user.
I too faced the same problem. Despite of following every Answer it didnt work.
Then I changed the "Inherits=namespace.class" to "Inherits=fully qualified assemble name" i.e "Inherits=namespace.class,assemblyname, Version=, Culture=, PublicKeyToken="
Hope it helps.
This can also happen if you accidentally forget to set your VS solution to "Multiple Startup Projects" if you are running a Web and WebApi from the same solution.
You can check this by right-clicking on Solution in the Solution Explorer and select 'Properties". Then look for 'Startup Projects'.
I spent multiple days on this issue. I finally got it resolved with the following combination of suggestions from this post.
Change platform target to Any CPU. I did not have this configuration currently, so I had to go to the Configuration Manager and add it. I was specifically compiling for x64. This alone did not resolve the error.
Change the output path to bin\ instead of bin\x64\Debug. I had tried this several times already before I changed the platform target. It never made a difference other than getting an error that it failed to load the assembly because of an invalid format.
To be clear, I had to do both of these before it started working. I had tried them individually multiple times but it never fixed it until I did both.
If I change either one of these settings back to the original, I get the same error again, despite having run Clean Solution, and manually deleting everything in the bin directory.
The solution for me wasn't any of the above.
I had to delete (and not recreate) Global.asax and Global.asax.cs.
These files existed in the folder, even though they weren't referenced in the project.
Apparently the build still saw them.
Since I use OWIN with Startup.cs, the Global.asax file was obsolete and there was no issue with deleting it.
Yes, I read all the answers. However, if you are me and have been pulling out all of what's left of your hair, then try checking the \bin folder. Like most proj files might have several configurations grouped under the XML element PropertyGroup, then I changed the OutputPath value from 'bin\Debug' to remove the '\Debug' part and Rebuild. This placed the files in the \bin folder allowing the Express IIS to find and load the build. I am left wondering what is the correct way to manage these different builds so that a local debug deploy is able to find and load the target environment.
I also got the same error...check the name of the Application you developed properly ie. the namespace and the assembly name alloted and also try physically changing the name of the folder created for the application, all of this should be same as the name in the above namespace present in the file global.asax
I also got the same error...check the IIS Configuration of your Virtual Directory and be sure that Properties - ASP.NET - ASP.NET Version is the same of Project Properties - Application - Target Framework. (That fixed this error for me.)
My app was built in an older version of VS, and didn't have a bin folder. I had upgraded it to a newer version, and had a nightmare getting it to deploy. I finally tracked this error down to the Project > Properties > Application. The Target Framework was set to 2.0; changing it on the server to match in the IIS Manager/App Pool solved the issue for me.
I found that changing the Namespace on the project, without refactoring that across the whole solution was my problem. Check your project Properties and see what your namespace is, ensure that lines up, across the board.
The problem for me is that I didn't include global.asax.cs in my project. And because I was copying files from a .net 4.5 to a 4.0 I didn't comment out lines that are not needed in 4.0. Because it was not included visual studio compiled it anyway without issues. But when I included it, it highlighted the lines that cause problems.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
//using System.Web.Http;
using System.Web.Mvc;
//using System.Web.Optimization;
using System.Web.Routing;
namespace YourNameSpace
{
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
//GlobalConfiguration.Configure(WebApiConfig.Register);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
//BundleConfig.RegisterBundles(BundleTable.Bundles);
}
}
}
I spent literally a day trying to resolve this.
The only thing that worked was deleting the .sln file, creating a new one, and adding the projects back in one by one.
¯\_(ツ)_/¯ - Programming - ¯\_(ツ)_/¯
For my case, the web assembly was part of GAC... so after build, it need to installed in GAC and it worked.
I encountered this error message and eventually discovered that the error message was misleading. In my case there appears to have been a routing issue in IIS which caused the global.asax from another site on the web server to be read thus generating the error.
In IIS, my site was bound to http:*80:webservices.local and contained an application called MyAPI. I received the dreaded message when calling the MyAPI application using the web server's ip address.
In order to successfully call my application I had to add a host file entry for webservices.local on all of the machines that called the MyAPI application. Then all of my requests had to be prefixed with http://webservices.local/MyAPI/ in order to route correctly.
I tried absolutely everything here and nothing worked. My project was in VS 2013. I have since upgraded to VS 2015 and have been creating all of my new applications in 2015 but loading, compiling, building etc all of my old apps that were built in 2013 in that version.
I ended up just loading the solution in 2015 and it resolved it for me.
I am very confused right now. I have VS2008 at my job right now and I have a weird behavior that I have been searching for a while now.
When I compile the project, it works fine, but in runtime I have an error saying object not defined or something like that. The problem is that the imports/using is missing in my class but why does it compile?
In fact, I want to be able to see that error when compiling not when running the webapp.
REEDITED: Here is an example. Lets say i want to use a typed list, I am declaring my object list(of int) for example without having added my imports (system.collection.generic) in the class. then I compile, it works and then I run it, it fails because of the imports missing. is this normal behavior or not?
REREEDITED: I just noticed that the DLL of all my references were not copied in my bin folders even though all of them are set to "Copy local = true". Is it possible that it has to do with our shared directory (all external dlls) being on a network drive (\server\shared). I am really out of ideas on this issue....
problem was because we were having the classes in the app_data folder
The answer to the current question - why you are getting this error - is that ASP.NET does not show many errors at compile-time. You will need to manually go through the application to verify that all pages work correctly. This is very common with ASP.NET development, due to the nature of the environment.
If you post the real errors (probably should be as another SO question), we can perhaps help you with them.
Remove all the dll, etc from bin...
rebuild the whole solution then run
It should run fine...
I could use some help trying to track down an intermittent error that I've been having with our ASP.Net project for quite some time.
Intermittently when building the solution, the build will fail with the error "/: Build (web): Object reference not set to an instance of an object." The error has no associated file, line, column or project information. The weird thing about the error is that it will go away on successive rebuilds and doesn't seem to result in any run-time errors that we've come across once the build is successful. Sometimes the error will pop only once, sometimes 3-4 times, but eventually the build will finish successfully and then seems to build just fine each time after. I haven't been able to nail down a pattern as to why and when the error will happen, and since it always eventually builds it hasn't been a critical problem for us. Just an annoyance. But one that I want gone for obvious reasons.
I guess I should add that this is an application that was originally developed in ASP.net 1.1 and converted to 2.0 and I inherited it somewhere down the line after that, so I don't know when the problem originally surfaced. As far as everyone here is concerned, it's always been there.
Obviously I'm not expecting someone to pick out the cause of my problem as that would require them to look at our entire solution to pick out potential problems. Just hoping someone can give me a couple fresh ideas as to how to go about tracking down the actual source of the error in code. It has to be coming from somewhere, right? How would you go about finding out where?
I've seen this when you have a web control in a page where there is invalid HTML. If your codebehind is trying to do something with the control, it won't be able to find it and will give you Object Reference... error at compile time. In my experience, it doesn't create a runtime error, and the project will build if the file in question is closed at the time of build. HTH, Good Luck!
Run this command at the command line and see if you get some more detailed information
%WINDIR%\Microsoft.NET\Framework\v3.5\msbuild.exe YourSolution.sln /v:n
To follow up on this problem, we never did track down the origin of the error but it disappeared when we upgraded to Visual Studio 2008 and converted the project to a Web Application.
The first thing I'd try would be to increase the compiler verbosity. This can be set in the Visual Studio options - e.g. "Tools->Options->Projects and Solutions-Build and Run->MSBuild project build output verbosity" for VS2005. If you set it to diagnostic then it should tell you what it's doing at the time the exception is raised at the very least.
I had this problem for a long time and finally found a solution that work fine for me.
It doesn't make sense to me... but altering my web.config file with the following gets definitively rid of this intermittent build error :
<buildProviders>
<add extension=".rdlc" type="Microsoft.Reporting.RdlBuildProvider, Microsoft.ReportViewer.Common, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
<!-- add this line below -->
<remove extension=".rdlc"/>
</buildProviders>
Hope this help !
I had this at build time when my project contained custom datasources (my own objects returning collections) with compile errors (that is, my objects had errors).
You'll also get this error if you try and add a datasource and your project doesn't have any datasources in the project's root (e.g. if you've put all your datasource classes in a subfolder). The only solution I found was to create a datasource in the project's root.
Sorry not to be more precise, but there seems to be several things that can go wrong with datasources/objects at compile-time.
An "Object reference not set to an instance of an object" is clearly a run-time error, not a compile-time error. So what that says to me is that Visual Studio is choking on something, which may not necessarily be in your code, or which something in your code is only indirectly causing.
Next question I'd ask: Does this happen only in Visual Studio, or does the same thing show up when you build using MSBuild or CSC?
What's really odd is that it's a run-time error. You shouldn't see that at compile time. Do you have any pre- or post- build steps attached to the solution? Any unit tests you're including with your 'build' process?
Where does this error show up?
Check the Application Log of your Event Viewer - It should tell you where the exception is being thrown.
Just to clarify, is it the compiler itself that is choking? Are you doing anything weird with #define and #if directives in your code? Maybe something is being done out of order at some point... Just a thought...
See if there are any post-build events that could be failing. These can be found on each project's property page.
Try using Rebuild Solution instead of Build Solution. You may need to add Rebuild Solution from Tools > Customize. If your web app installs or registers any windows services, and those services are started, Rebuilding plows through those types of problems.