You can try below things to narrow down the issue:
1. Try to clear TFS cache in your client machine, then try it again.
The corresponding Tfs folders to manually delete are as follows:
Tfs 2017: "%localappdata%\Microsoft\Team Foundation\7.0\Cache\"
Tfs 2015: "%localappdata%\Microsoft\Team Foundation\6.0\Cache\"
Tfs 2013: "%localappdata%\Microsoft\Team Foundation\5.0\Cache\"
Tfs 2012: "%localappdata%\Microsoft\Team Foundation\4.0\Cache\"
You can copy and save the following content to a .bat
file, then execute on the client machine to delete the caches.
@echo off
ECHO **********************************************************
ECHO Delete the Tfs 2017 client cache
ECHO **********************************************************
rmdir "%localappdata%\Microsoft\Team Foundation\7.0\Cache\" /s /q
ECHO "All Done!"
2. Querying Lab Environments Using TFS Lab Management APIs, then compare with the environments in MTM, to check if there are any differences (NOT EXISTS ones).
3. Delete Lab Environments with tfsconfig lab /delete
command.
This command will remove all group hosts, library shares, and environments from team project collection.
Recreate the lab environments, see Creating Lab Environments
If that still doesn't work, then I'am afraid that you have to ask the admin to grant the permission to access the database, then try the solution mentioned in this link.