- did installation of newer Quartus versions make this stop working?
>>No, We are using multiple Quartus installed in systems. However sometimes files may be corrupted, try by reinstalling the Quartus.
- because my subscription licence is now past expired?
>>Without license, We can create a projects using Quartus tools without Analysis & Synthesis.
So license may not be an issue.
Let me know if this has helped resolve the issue you are facing or if you need any further assistance.