I can’t get Collab to work. The top toolbar and button are gone and in the services tab click Open the Collaborate toolbar or Open History Panel both don’t work.
Someone please help.
Im having the exact same problem
I closed the project and went to project folder>Packages and deleted the manifest.json file.
Re-opened and it was back
Unity has a bad habit of working under the illusion that their products do not contain bugs. Instead of giving an error-code when something doesn’t work it just fails silently.
What worked for me:
Go to Packages folder and move/rename the manifest.json file. Restart and let Unity reload everything. Then fix up your missing packages.