The first step would be to check your DEX.INI file to make sure Synchronize = FALSE
The top 3 lines should read:
Initial = FALSE
Synchronize = FALSE
AutoDisplayUpdate = TRUE
If the DEX.INI file matches above, next check permissions on the GP Install folder
An option is to change the GP User Group security to 'Full Access' - run utilities - then go back in and change the permissions back
If you are still having an issue, go to the Advanced button and check the box for 'Replace all child object permission entries with inheritable permission entries from this object - and click the Enable Inheritance button above
If the DEX.INI file matches above and the permissions are correct, check to make sure the company was created correctly and pointing to the correct folder