I am encountering with an issue with the latest version, whenever I tried to save after editing parts I get the something went wrong prompt and had to restart. No matter how many times I restart or even redownload the editor and start over I still received the same issue.
The funny part is, a few hours ago the editor was actually run fine and able to save after editing parts, but I've encountered a small issue couple of times where the editor suddenly duplicating parts after saving, so I reloaded backup saves and do it again. After a few times retrying, I suddenly began encountering the fatal issue above, and was unable to fix it ever since.
Update:
I seems to be able to get it to work now after redownloading the editor again.
I've also figured out how to get around the second issue (where parts are getting duplicated after saving). Whenever you're about to save for the new part that you've just created, make sure to complete every step that you've planned to do with it before pressing the save button (for example: increase the quantity, assigning the parts to each driver, etc).
Because once you've save it, but wanted to further edit it again and save once more, the editor will just somehow duplicate that part. So if you wanted to avoid seeing a list of duplicated parts on the list, make sure you completed everything all at once for one part at a time before saving it.