Error loading file or assembly in Web Application - asp.net

Question

i need some pro help here,
I'm trying to install the DevInfo 7 Web application on my server, had A LOT of problems with SQL Server and IIS, after 2 days, i managed to fix it, but now that IIS and SQL are working fine, i can't get past this error because i have no idea about this language (btw, i'll add some tags, but as i don't know this language, i'm not sure they are actually related to the question, if i chose a tag wrong, tell me that i take it of!)
If somebody can explain to me what's wrong, or how to fix it, i would appreciate, as i'm not creating a Web Application (i have no idea on how to do so), and only trying to install one, i may not understand (please be as simplistic as you can)
I dunno if this changes something, but i'm installing it on a Windows Server 2012, x64...
Here's the error:
Server Error in '/devinfo' Application.
Could not load file or assembly 'DI5_INIFile' or one of its dependencies. An attempt was made to load a program with an incorrect format.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.BadImageFormatException: Could not load file or assembly 'DI5_INIFile' or one of its dependencies. An attempt was made to load a program with an incorrect format.
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Assembly Load Trace: The following information can be helpful to determine why the assembly 'DI5_INIFile' could not be loaded.
WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
Stack Trace:
[BadImageFormatException: Could not load file or assembly 'DI5_INIFile' or one of its dependencies. An attempt was made to load a program with an incorrect format.]
System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +0
System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) +210
System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection) +242
System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +17
System.Reflection.Assembly.Load(String assemblyString) +35
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +122
[ConfigurationErrorsException: Could not load file or assembly 'DI5_INIFile' or one of its dependencies. An attempt was made to load a program with an incorrect format.]
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) [phone]
System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +503
System.Web.Configuration.AssemblyInfo.get_AssemblyInternal() +142
System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +334
System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath) +203
System.Web.Compilation.BuildManager.ExecutePreAppStart() +152
System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +1151
[HttpException (0x80004005): Could not load file or assembly 'DI5_INIFile' or one of its dependencies. An attempt was made to load a program with an incorrect format.]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) [phone]
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +159
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) [phone]

Answer 1

It sounds as if you have entered .net Version Hell. I've had this problem when there are conflicting dll versions.
Things to try:
1 - Clean your solution (Right click on the top of the solution tree in Visual Studio and click "Clean"), then do Rebuild All.
2 - If that doesn't work, clean out the ../bin/Debug folder for you project, and repeat step 1. If this is a web application and you have a local version of IIS running, you should consider doing an IIS reset first. This will release any locks that processes may have on dlls in your bin folder.
3- In addition to step 2, you could clear out the ../obj folder too. The clean and rebuild should do this for you, however.
4 - One more thing to try is clear out the temporary asp.net files:
del /F /Q "%SystemRoot%\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files"
5 - Failing that, you will need to look at which project is trying to reference 'DI5_INIFile' and check its version number (right-click on the dll > properties > version) and see if it's in your web.config under a different version number.
If it is, you could remove the referenced assembly from your project and try to re-add it again.
Hope that helps!