- You have installed Visual Studio 2012 recently while having Visual Studio 2010 SP 1
- You then open the Servers and connect to an SQL server (either 2008 or 2012) from VS 2010
- Try to create a table in one of the connected database.
- You get an error "The specified module could not be found. (Exception from HRESULT:0x8007007E)"
- Additionally if you want to design the DBML with LINQ to SQL, you cannot drag a table into the Design Surface
When you installed VS 2012 it has "corrupted" with the following DLL version that does not work right in VS 2010.
C:\Program Files (x86)\Common Files\microsoft shared\Visual Database Tools\dsref80.dll
Note that "repair" of Visual Studio will not work. Do not go down that path! You pretty much need a completely clean installation of this, as it is in the shared file. So do not waste your time.
Find a system that never had a Visual Studio 2012. Harvest dsfre80.dll and copy this to the same location on your damaged computer and you are good to go.
At worst case, create a Virtual Machine, for example use the free Virtual Box, install a VS 2010 on it and harvest the file.