Uninstalling content templater 10.1.0 pro causes...

I intend to change from content templater pro version to free version. Then I tried to uninstall content templater 10.1.0 PRO through joomla extension manager. Suddenly my id was forced to logoff. Since then I can not login because of no access authority message. Other members as same.
I tried a few ways to circumvent the problem and failed. Finally I restored the site using akeeba bakup file.
Please advice me how to solve or avoid the problem.

Thanks and Regards, T Sejimo

I uninstalled content templater through joomla extension manager instead of regular labs extension manager. The reason is because I could not find uninstall button in regular labs extension manager. Is it the problem to use joomla extension manager for uninstallation?
According to my experience, both uninstallation way has been no problem.

Thanks and Regards, T. Sejimo