Those temporary files are created by the ASP.NET compiler under c:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files
When those files get funky and you see errors like this, the only way I know to solve it is to stop IIS or stop the web site temporarily and delete all the files in the temp folder. Then when you start the web site again they will get generated again and usually that will solve the problem.
You may need to get your host to help.
Hope that helps,