Request APM 10.5.0 Hotfix#6 and APM 10.5.1 Hotfix#5 from Support and deploy. Or upgrade the .Net agent to APM 10.5.2 and later where this issue is resolved. The file changed is MVC.ext.dll.
The implementation steps are the following:
1. Stop the monitored .NET applications.
2. Backup and replace MVC.ext.dll under the <.NET Agent Install>\wily\ext\.
3. Check the GAC (Global Assembly Cache) to see if the MVC.exe.dll can be found there. If found, then back up and then delete the DLL file from GAC.
4. Restart the monitored .NET applications.