You are sharing SDL Trados Studio projects via a network drive with several Trados instances accessing the same project folder.
You are experiencing issues that include but may not be limited to:

• Changes one user makes are overwritten by changes from another user.
• You receive error messages or experience performance issues that do not occur if the project is saved on a local drive
• In GroupShare projects, you are prompted to log in with different credentials than your own
• Translation memories/termbases become disabled (if users that do not have access to the resource work with the project or if your network drive is mapped with different letters for different users)

While storing projects on a network drive may work if the network drive is sufficiently reliable and fast, it is important that each user stores the project in a folder that only their Trados instance accesses.
Note: SDL Support does not provide assistance for issues that arise because projects are shared via a network drive.

Solution: SDL Trados GroupShare

If you would like to share projects with your colleagues and external users, consider the SDL GroupShare project server as a solution.
If you are using GroupShare: It remains important that each user stores the local copy of the project in a folder that only their Trados instance accesses. Projects are synchronized via GroupShare instead.