If you’re getting an error similar to the one below:

[C:\WINDOWS\assembly\GAC_MSIL\Microsoft.SqlServer.SmoEnum\9.0.242.0__89845dcd8080cc91\Microsoft.SqlServer.SmoEnum.dll] InternalsVisibleTo declarations cannot have a version, culture, public key token, or processor architecture specified. (ObjectExplorer)

If you’re getting this error when you try to connect to a SQL Server 2005 database using SQL Server Management Studio CTP, it’s because you installed .NET Framework 2.0 while still running a CTP (Beta) version of SQL Server 2005.
SQL Server 2005 CTP can only run with the beta version of .NET Framework 2.0. You must either upgrade to the final release of SQL Server 2005, or downgrade your .NET Framework version to 2.0 beta.