I have massive problems with saving a BPMN model. This problem exists for at least 6 years (see other entries in forum) with no reaction from the product side. Since I just lost a big model, which I build for a customer (who uses ARIS) I have a clear recommendation ...
What happend: When I try to save a model, I get the error message "???" and a dump with a stack trace of an Internal Java Error. But what is even more worse: My (previously saved) existing model is lost as well, there are only some fragments left.
Have you logged a support call provding all of the relevant information about your situation? Can you reproduce the problem? The problem exists for 6 years! Do you have all of the history of claims you submitted from all of the cases?
Surely, you should escalate this to the highest authority @SAG.
That said, what percentage of people in the community have this problem? It strikes me that you could have issues that are more related to your own deployment which require analysis and troubleshooting. Have you considered this?