问题
I tried to look at the data connection between my visual studio and SQL server, however it keeps on saying "Unable to find the requested .Net Framework Data Provider. It may not be installed." How can I get this fixed please? It was working before, suddenly it stopped working. I checked in the C:/windows/assembly System.Data.SQLClient is not there.
回答1:
Ensure that the provider factory is registered with an appropriate entry in the machine.config.
回答2:
In my case I was selecting the worng reference. For some reason x86 works, while x64 does not (in my case). Simply don't forget to reference System.Data.SQLite.dll and/or System.Data.SQLite.Linq.dll.
来源：https://stackoverflow.com/questions/9591038/unable-to-find-the-requested-net-framework-data-provider-it-may-not-be-install