问题
So I have a project that has been around since 2011 with intermittent additions for Libraries and additional projects within the Solution. I am attempting to update it to 4.7.1 for all libraries and projects to which I have all the libraries and projects set to the 4.7.1 frameworks in Properties -> Application -> Target framework, however, I am getting warnings, debug errors, and a slew of other issues related to framework where:
1) when I try to debug it says "this error is because you are running a .NET Framework 3.5-based application in .NET Framework 4."
1b) generates an error in debug mode (it is linked with the error message in 1)...
2) I search all web.config files and all are showing 4.7.1 and no other references to any of the old projects
3) I receive an error message for mscorlib to which I tried to scour stackoverflow and MSDN but none of the solutions are working (tried removing and adding dependencies/references, etc.) =
No way to resolve conflict between "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" and "mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e, Retargetable=Yes". Choosing "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" arbitrarily.
What are all the sections within project I should be looking for to find where the error is occurring? I am trying to create a checklist of all the different potential areas that it could generate from and start checking them off my list one by one...
any suggestions?
Thanks in advance
来源：https://stackoverflow.com/questions/47859720/updating-to-net-4-7-1-framework