OK, it's late at night, and I did something that Trevor likes doing.  :)  I went looking for trouble.  But hey, I had a good reason, and had been planning this experiment for weeks already.

 

My current accounting is still my own FoxPro concoction (started in 1992 and updated a few hundred times), and for the last few years I knew I would have to move it.  Besides export/import issues, I have several extra fields of information that I need to preserve (even if not accessible outside of raw XML editing), so I edited a good GnuCash native XML file by adding a secret payload in one existing transaction with <mynewtag>mypayload</mynewtag>, at the same level as the other fields of that transaction.  I was hoping it would be ignored on load, and restored on save.

 

The result:  GnuCrash crashed totally while opening the edited XML file!  Yeah, just crashed with a crash message and self-quit after that.  Is GnuCash that unstable???

 

BTW, a simple raw XML edit of an existing text field of a transaction works fine, and is then shown in GnuCash when the file is opened.