Error:
when click "New Database Diagram", a error popped up and said "Attempted to read or write protected memory. This is often an indication that other memory is corrupt. (Microsoft.VisualStudio.OLE.Interop)"
Related Link:
http://*.com/questions/16856548/database-diagrams-inaccessible-after-change-of-database-name
解决方案：
You will need a second computer with either SQL Server and / or Visual Studio installed. Then use the second computer to copy the .dll files specified in the steps below, and replace the corresponding files on the computer where the database diagrams is not working.
Step 1: Replaced the following file: C:\Program Files (x86)\Common Files\microsoft shared\Visual Database Tools\dsref80.dll (Note: this one may not need according to link 1 and link 2's problem is different)
Step 2: Replaced all files in the following folder: C:\Program Files (x86)\Common Files\microsoft shared\MSDesigners8\