Sql Server Management Studio: Change Prefix or Suffix characters
Solution 1:
I encountered the same error ('Invalid prefix or suffix characters. (MS Visual Database Tools)'), and it was because I was trying to use SSMS 2008R2 with an SQL-Server 2012 database.
I have both SQL Server 2008R2 and 2012 installed on my machine, and I was using the wrong SSMS.