ASPNETCOMPILER error ASPCONFIG: Could not load file or assembly 'Microsoft.VisualBasic.Activities.Compiler' or one of its dependencies

Question

I just upgraded my project to Asp.Net 4, from 3.5. When the build kicks off from TeamCity, I get the following error:

[Project "Website.metaproj" (Rebuild target(s)):] C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe -v /Website -p Website\ -u -f PrecompiledWeb\Website\
[12:11:50]: [Project "Website.metaproj" (Rebuild target(s)):] ASPNETCOMPILER error ASPCONFIG: Could not load file or assembly 'Microsoft.VisualBasic.Activities.Compiler' or one of its dependencies. An attempt was made to load a program with an incorrect format.
[12:11:50]: MSBuild output:
[12:11:50]: Copying file from "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\Dependencies\wnvxls.dll" to "Website\\Bin\wnvxls.dll".
[12:11:50]: Copying file from "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\Dependencies\wnvxls.xml" to "Website\\Bin\wnvxls.xml".
[12:11:50]: C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe -v /Website -p Website\ -u -f PrecompiledWeb\Website\
[12:11:50]: ASPNETCOMPILER : error ASPCONFIG: Could not load file or assembly 'Microsoft.VisualBasic.Activities.Compiler' or one of its dependencies. An attempt was made to load a program with an incorrect format. [C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\Website.metaproj]
[12:11:50]: Done Building Project "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\Website.metaproj" (Rebuild target(s)) -- FAILED.
[12:11:50]: Done Building Project "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.sln" (Rebuild target(s)) -- FAILED.
[12:11:50]: Done Building Project "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.sln.teamcity.patch.tcprojx" (TeamCity_Generated_Build;TeamCity_Generated_NUnitTests target(s)) -- FAILED.
[12:11:50]: Build FAILED.
[12:11:50]: "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.sln.teamcity.patch.tcprojx" (TeamCity_Generated_Build;TeamCity_Generated_NUnitTests target) (1) ->
[12:11:50]: "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.sln" (Rebuild target) (2) ->
[12:11:50]: "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\Website.metaproj" (Rebuild target) (3) ->
[12:11:50]: "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.Other\MyProject.Other.csproj" (Rebuild target) (5) ->
[12:11:50]: (CoreCompile target) ->
[12:11:50]: Helpers\ProgramHelper.cs(40,21): warning CS0168: The variable 'ex' is declared but never used [C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.Other\MyProject.Other.csproj]
[12:11:50]: "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.sln.teamcity.patch.tcprojx" (TeamCity_Generated_Build;TeamCity_Generated_NUnitTests target) (1) ->
[12:11:50]: "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\MyProject.sln" (Rebuild target) (2) ->
[12:11:50]: "C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\Website.metaproj" (Rebuild target) (3) ->
[12:11:50]: (Rebuild target) ->
[12:11:50]: ASPNETCOMPILER : error ASPCONFIG: Could not load file or assembly 'Microsoft.VisualBasic.Activities.Compiler' or one of its dependencies. An attempt was made to load a program with an incorrect format. [C:\Program Files\TeamCity\buildAgent\work\8bbb8fc03bd91944\Website.metaproj]
[12:11:50]: 1 Warning(s)
[12:11:50]: 1 Error(s)
[12:11:50]: Time Elapsed 00:00:31.48

I tried copying the .net framework reference assemblies to C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0 thinking that would fix things, but still no luck. Any thoughts?

Answer 1

This error had to do with class libraries in the solution referencing older (v3 or v3.5) system assemblies. Those class libraries were referenced by my website, so the system assemblies got copied to the bin folder along with the class libraries. Maybe the system assemblies in the 3.5 directory have different permissions than the 4.0 directory and when the aspnet_compiler tried to load them from the bin directory, it barfed.

After going through each csproj file and updating <RequiredTargetFramework> values to 4.0, everything is working as expected.

Answer 2

For me it was indeed an x86/x64 mismatch. I solved it by specifying the path to the x64 MSBuild through the MSBuild environment variable:

Answer 3

I got the same error building the .csproj_deploy from VS. All other projects including the web in the solution built fine. There was actually this Microsoft.VisualBasic.Activities.Compiler dll in my web bin folder. When I clicked build/clean solution, all the files in the folder got deleted except this. I manually deleted this file and built again and it built fine. This time, I do not even see this file in the bin folder.

Answer 4

Looks like an x86/x64 mismatch - I'd strongly recommend actually using the framework installer, than hacking it by copying the files by hand

Answer 5

I found the very simple accepted solution presented here fixed the issue for me, this being installing the Windows SDK for .NET Framework 4 (or the equivalent for your Windows version).

Note the comment on the accepted answer that says "Intellisense and Reference Assemblies" are the only features from the SDK needed to fix this issue.

Answer 6

The simple solution that worked for me was to modify the TargetFrameworkVersion line of the .vbproj file. Simply changing "v4.0" to "4.0" removed all of the copmiler errors and fixed my intellisense issues (asp.net tags were not being recognized).

Answer 7

We had this error when switching our hosting environments (to the new web server with IIS).

The fix was:

• Either change the Application pool / Advanced settings, and set Enable 32 bit applications to true, or
• Delete all assemblies from the bin folder that already belong to the framework (e.g. we had System.Data.dll in our bin folder, which was obviously built for 32b - deleting it fixed the issue)

Answer 8

I found that I had an unnecessary reference to the 'Microsoft.VisualBasic.Activities.Compiler' dll. Once I removed the reference, all things worked.

Answer 9

If you are building a web project in x64 in Visual Studio and running on IIS Express you must enable the following setting:

Tools --> Options --> Projects & Solutions --> Web Projects --> Use the 64 bit version of IIS Express for web sites and projects