An old version of Visual Studio, together with a DotNetNuke installation gave a missing library error.
The missing library was System.EnterpriseServices.dll
A more complete error report is given below:
Server Error in '/dnn4.5.1' Application. Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. Compiler Error Message: BC2017: could not find library 'C:\WINDOWS\assembly\GAC_32\System.EnterpriseServices\2.0.0.0__b03f5f7f11d50a3a\System.EnterpriseServices.dll' Source Error: Source File: vbc : Command line Line: 0 C:\WINDOWS\system32> "C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\vbc.exe" /t:library /utf8output /R:"C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\dnn4.5.1\510f65ef\fba7a194\assembly..." ... Version Information: Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.210
Previously errors tended to be resolved by deleting the temporary directory or by ensuring that the correct permissions had been assigned.
Initially I had checked the permissions for the directories mentioned, ensuring that both ASP.NET and Network Service had both read and write access.
Unusually, I found that to resolve this issue I had to re-install the .NET framework.
