I had a project targeting .NET Framework 4 which for a variety of reasons I had to downgrade to target .NET 3.5. This produced a rash of System.Configuration.ConfigurationErrorsExceptions whenever the code tried to access My.Settings. The error message was "An error occurred creating the configuration section handler for userSettings/ACal4.My.MySettings: Could not load file or assembly 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. I searched the solution for every instance of 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' and changed it to 'System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' but the error persisted. I looked in the project file but found nothing relevant there.
I tried recreating the project from scratch in NET 2 and upgraded to NET 3.5 and I still got the same error even though the new project had never referenced 4.0! Could there be some kind of cache that I am missing?
I am using VS2013.
Mike VE