I have an application that is getting yellow asp.net error screens appended to the response. The page will look normal, and then have the yellow screen below the Html. I have narrowed this error down to the application reseting during the response, and the session dying. So if I start loading a page, and save the web.config, it gives me a session-related error appended to the page. I am going to use the sessionstate service to fix this, but I am curious if anyone has ever seen a yellow screen actually appended to their application html. This website even uses customerrors="on" with redirects to 500 error pages. How can I prevent this from happening? Do you think the sessionstate service will help?
Thanks
sounds like you have a web control on the page that in turn calls another web app or service to generate the response, and that web app is the one that is erroring....
Any response.Flush calls in your code? That's the only thing i could think of, but no, never seen that happen.
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I am encountering a strange issue which is only affecting several users from an over 7000 user-base. Having searched the web for several hours to no avail, I'm hoping someone here can help!
I have an ASP.NET 2.0 website and when certain users try to access the home page (Default.aspx) they receive a white screen with no content loaded. This issue is occurring both in production environment and if I run the solution against a copy of production data. So I am able to replicate the exact same issue when I pseudo the problematic users.
When debugging the application in VS2005 and set a breakpoint in the code behind in the Default.aspx, the breakpoints are fired/hit so I know the request is working. The problem seems to be once the server has finished serving the request, the response back to the client/browser is empty.
Here's another strange thing I've noticed. If I alter the HTML in Default.aspx by adding a new white line or whitespace, the page will load fine for the same set of users. I thought I had resolved the issue with this fix but unfortunately the white screen issue just manifests itself once again.
Within Default.aspx, there's some AJAX requests using jQuery .load function but this can't be the issue because this functionality exists for every user of the site. The only variable is the amount of content returned within this request can vary depending on the user. But why would it resolve itself when I put a whitespace or whiteline in the page and then manifest itself hours later?
Another thing to note is it's only Default.aspx that is encountering this issue. If I browse to another page by typing in a page in the address bar, the page is served OK.
Hope someone can point me in the right direction on how I can debug or even resolve the issue.
It sounds like your ajax is the cause but without seeing some code, it's difficult to know why.
It could be a timeout, or an error that is preventing the ajax from completing it's function.
You need to use a tool like Charles or Fiddler to debug what is happening whilst the page loads whilst logged in as these users. In a nutshell, a tool like Charles will display all the detail surrounding requests made and responses served to the browser, including any failed responses.
I think it has to do with http headers, caching or encoding. But I cannot tell more without code.
Is output caching enabled for this page?
Can you give us the raw http headers for both the request and response?
If a white screen appears, will it be fixed by pressing ctrl+f5?
We have been trying to figure this one out for a while now, without any luck.
The symptoms are as follows:
After some idle time of a specific ASP.NET 2.0 application (can be from several hours to days), one of the pages in my application stops working.
When viewing the source of the page I see many elements missing, elements that are usually there, such as: reference to WebResource.axd, the __doPostBack() function, all of the UserControls and more.
A reference to ScriptResource.axd, and the __VIEWSTATE are there.
After recycling the app pool, the application starts working correctly again and everything renders well.
This only happens on a specific server, when deploying the same application on a different server, this error does not occur.
The page that the error occurs on has only one UserControl which is not rendered when the error occurs. Nothing special happens when this page is loaded.
We tried doing periodic client refreshes, but that did not help either.
Thanks in advance.
It was a caching issue. There was a part in the code that hid specific controls when the cache was invalid. That explains the missing code parts.
I am still not sure why the cache was invalid on that specific server.
I have an ASP.NET website that has been deployed since 2008 with plenty of users. From time to time, I've made updates to the site and uploaded those changes to the server without problems.
However, today, I'm trying to run the site on my development environment and I keep getting errors any time the code tries to access session state. It appears System.Web.HttpContext.Current.Session is always null!
Any suggestions on where to look? It's been a while since I worked on it and am not 100% sure if I've worked on it with the current version of ASP.NET (4.0).
Other than that, the code's been working fine and I haven't made any changes since it was last working.
More Information
I've spent all morning on this but I apparently have a larger issue.
If I step through the code, I see that my page Load handler executes. At this point, Session is not null. After that, my specialized master page executes. After that, my general master page executes. I then step through load events for a couple of controls. This all seems very normal.
Then, if I keep executing, suddenly I'm loading a specialized master page for another page and Session is now null!
If I hit F5, it the original page shows. But somehow it is causing the other page to load and without session state. If I turn off debug mode, it appears to run normally.
Obviously, I have something strange happening. I need to determine why the other page is being loaded.
Try to put a static page, something like Test.aspx and browse to that page. If it gets loaded, try to use Session property of the page in code behind. Do you still get the error? In that case, Session doesn't load. I suggest creating an HTTP Module and hooking into a method which is responsible for loading Session info. See what's wrong.
Just a guess - did you deactivate sessionState for any reason? Anything like this:
<sessionState mode="Off"/>
My apologies. The information I provided was completely misguided and was not sufficient to resolve the issue.
The problem was actually due to some custom error handling that redirected to an error page. This was configured in web.config. This error page was using the master page that my code was mysteriously executing.
Apparently, an error was occurring within the GridView control. This is ASP.NET code and not my own, so I was unable to step through it or catch it with a regular handler.
This was hard to understand. If I was executing the Load event handler of my error page, then it would've been obvious. But it appears to have skipped over that. Thus, my confusion.
Try checking the global.asax file or any other pre-load events and make sure the Session is not set to NULL explicitly.
Maybe your erring master page is calling code from some external class where the session object is not available?
I'm more into the LAMP stack, but I've been asked to work on a site that is running Windows and IIS 2008. I'm a beginner with IIS, so please be patient with me on this, and please ask me to provide more information if that is needed to determine.
I read the answer here (Slow first page load on asp.net site), but it seems like if I go to the site with one browser it takes long to load the first page, then fast on all other pages, then if I open up another browser, it's the same thing, so it's not something that is saved on the server, but per session?
Is there a way to have the application running at all times?
Right now it is taking 12 to 15 seconds for the first page to load.
I have access to the WebControlCenter and FTP.
I would look in the Global.asax page and see if there is anything going on when a session is started. There usually is a method in there called Session_Start that is called whenever a session is started. Also, it might have to do with the site being configured in debug mode. You can change the web.config setting to false, which has a big impact on performance.
I'm familiar with the phenomenon described in the question you've linked to, but your what you're describing does seem a bit odd.
firstly- try Jeff's suggestion and see if indeed there's something at the beginning of the session which slows it down.
If not- try answering this-
1. is the first page always slow or only on first access to it?
2. what happens if you open another tab in the browser (not a different browser)?
3. it's possibel that the page contains some heavy resources (like images, script files etc.) which are only downloaded on the first access to the page. try tracing your http responses you get and see what their sizes are.
4. try to enable trace on your web page to see the events which are taking the longest time (on aspx you need to add 'Page Trace="true"' to the page declaration)
hope one of these helps...
Have you tried a http debugger here? Lots of things could be going on here, but the fact that you get different behavior by using different browsers indicates it is probably some particular resource that is overweight.
I enabled tracing in IIS7.
I set those properties to true in the ASP tab of the IIS management tool:
appAllowClientDebug,
appAllowDebugging,
errorsToNTLog,
scriptErrorSentToBrowser;
To test it, I wrote a small classic ASP test page in wich I voluntary include a bug (bad activeX name).
My asp test page is rendered until the bug line is reached. The rest of the page is not rendered. I was expecting a 500 error code, but code is always 200. There is no error file in the FailedReqLogFiles folder.
Any idea someone?
OK, i think the issue is actually with Enable Server Side Debugging. You may have it enabled, but you should disable it instead.
The server thinks it should start debugging and tries to fire up a debugger, and then doesn't find one and just gives up! I'm sure this never happened prior to IIS7.
Glood Morning,
This problem was slowing our development significantly, because sql server errors were not displayed on the browser. Our Application Service Provider tried some settings, but couldn't get it to work. They sent me the settings and I accidentally did just two at once and our problem was fixed. They told me that asp was giving return code 200 instead of the error code.
Here is what worked for us:
The combination of "Send to Browser = True" and "Enable Server Side Debugging" = False" works.
I hope that helps others.
Tom Armstrong
Look at this and see if this is stopping you from getting the 500 error. Also, If the bug is handled through an exception handler in the activeX then you might not be seeing an error on the asp response.
http://classicasp.aspfaq.com/general/why-do-i-get-a-500-internal-server-error-for-all-asp-errors.html
200 OK is a Standard response for successful HTTP requests. The status code indicates that the client's request was successfully received, understood, and accepted.
We had this same IIS7 error happening. It was not returning any kind of error. There was no error message on the screen and no 500. The page just stopped rendering.
Is that what you are seeing? I can't remember what it was unfortunately, i think it was like something was handling the error. (If this is what you are seeing, i will keep trying to remember!)
I don't think this is it but it might be: go into Error Pages > Edit Feature Settings (hidden on the right panel) and select Detailed Error? That setting is also required and you didn't mention it.