UPDATE: The error is resolved starting with 2019.4 version. Please get the latest Studio version.
Device ID already activated - as I have mentioned before, this happens when you previously activated your Studio with a Trial key and after expiring you want to go back to using Community Edition.
Only in special situations the Trial can be extended or the Device ID released from our licensing server. So, since there are so many questions around this, here is what you can do in order to use Community Edition:
Install UiPath Community Edition
Connect Studio (the Robot in user-mode that comes with Studio) to Orchestrator Community Edition: https://platform.uipath.com/ as Development Robot
Studio will get its license through Orchestrator (since 2018.4 version)