"unspecified error" when working with MS VSS

[ssuser]

Hi, I'm using SourceSiteClassisc 3.5.3 with MS Visual SourceSafe as my default SCC provider. When open .sln file from Visual Studio .NET, I got "unspecified error", and it loads the files but they are not binded to vss. I tried to manually bind the project to vss, it would show "unspecified error" again and won't do the job. But if I switch my default SCC provider to SourceSite and then it works fine. But I need to have VSS as the defaul provider. I have two prjects with this kind of set up, and the other one is working perfectly. So, I don't think it's the problem of VSS. Can anyone help me with this problem? Thanks.

[SourceGear Support]

When you try to open this solution from VS.NET, are you using File > Source Control > Open From Source Conrol?

Also, was this soultion originally added with VSS or SOS?

[M.Meuwese]

I downloaded them with SOS. After creating a new solution and adding the webprojects, I can't bind them to SOS. Also 'Unsecified error'.

But I get also an error when starting:

'The solutions appears to be under source control, but it's binding cannot be found. It is possibl that the MSSCCPRJ.SCC file or another item that holds the source control settings for the solution, has been deleted.