I am getting the same error. I uninstalled MATLAB Drive Connector several times, even deleted the folder C:\Users\Michal\AppData\Local\MathWorks\MATLABConnector and the old Matlab Drive folder but after new installation I am getting the same error. So I turned off my firewall (I use only windows defender) but Connector still hasn't been able to contact MathWorks servers.
When I click on MATLAB Drive online icon I am able to reach the site and log in to the drive. When I try to access MATLAB Drive via Matlab, it tells me, that the folder does not exist but it has been configured in Matlab Connector. When I installed it for the first time, it was working fine, but after a while stopped working. Please, what should I do to solve that?