In order to use project planning or user assignment functionality, you have to map vendors created in TBM with users created in Language Cloud, so the system will keep user IDs and operate with these IDs to correctly assign vendors selected in Translation assignments.

In the vendor list, you can click RWS button, which contains the following actions 

• Link with Language Cloud user. Allows to map current vendor with a specific Language Cloud user.
• Unlink from Language Cloud user. Removes mapping from a user.
• Import missing vendors. Downloads all users from your Language Cloud instance, selects users which are not mapped with any TBM vendor, and creates new vendors for each of non-found user. Only first name, last name and e-mail fields are filled for newly created users. Other data, like addresses, supported languages, etc., should be filled manually.