This is the for 90% of Error 30 cases in ETABS 2016.

For networks or standalone environments failing to initialize the Sentinel RMS manager, manually forcing Windows to look at the local host path will bypass the Error 30 loop.

If you are using a standalone license, it may be corrupted or incomplete. CSI Knowledge Base Deactivate and Reactivate

For network license users, the machine cannot connect to the server, or the license server is not running.

Understanding why the CSI Licensing System rejects your file makes it easier to prevent the problem from reoccurring: