Was a solution to this issue posted? I have a similar situation ("internal error") in version 21.1.33 when saving. I can occasionally incrementally save if only modifying a fixture position/orientation.
I have several large DWG models that have been imported. The .c2p file is now 271 MB (277,936 KB). If I delete a large model, I can perform additional edits and save without issue.
Is this a memory issue? I am running in Win7 with 16GB on an HP ZBook 17.
Thanks in advance.