Iīve got the Error "Version Mismatch" here are some tipps to fix that:
1. Use the function in the launcher "force verify"
2. remove the gameclient.exe, verify, and put it back in.
3. Set File Permissions to the all STO Files to read/writeable
4. Approve the launcher Admin Rightīs (most Windows 7 an dvista users)
5. Check antivirus that it dosenīt block your launcher
Thatīs are my tipīs, after Tip 4. it works fine for me...