I was developing a tool for my personal use, and have had the same issue. The reason was some SQLiteDatabase.finalize() call. I removed all finalize calls from my code and the issue has gone. I don’t know if I did the right thing, but letting you know.
Is it possible to replicate this somehow? Would be great if you could share a snippet or some other example with us so that we can fix it.
I’m attaching a tool in zip archive (just changed the extension to xrnx). Also, I’m attaching a log from Renoise (the last crash info starts from line 40744). To replicate the issue just open the tool and scroll popup values quite often. After some time (30-40 seconds, sometimes a little bit more) it will crash.
Log.txt (1.8 MB)
tool.xrnx (8.8 KB)
P.S. Could be that I’m using finalize() not as it should be used, but I’m not a good programmer 
I don’t know if I should create another topic, or if writing in this is enough, but I see another issue. When I open Renoise my tool works as expected, but when I create new song or load an existing one I have to reload my tool for it to work properly. I have app_new_document_observable in my code, so probably it should reinitialize on new song load or creation. You have my code, so I won’t it post here, but if it needed, let me know.