It's a pain in the ass, with almost every update I need to delete my json-files and loose all my settings...
The logs are pretty useless, though I've activated extended logs.
I was able to reproduce the issue by taking your helium.json file and putting into my folder.
The issue seems to be related to the beta messge.
It should hopefully be solved in:
>>Could you create a testing-build, which logs reading these files - maybe even logs applying each setting?
That's a bit hard because they are automatically serialized/deserialized and will not give me much details.
What you could try is to:
1) Revert to an older build
2) Ensure that it starts and backup all JSON files
3) Upgrade to the most recent version
4) Try to start the version
If the crash occurs now, you can share the JSON files with me and I can review them further.
Can you isolate a case why this happens?
I know that you have mentioned it earlier, but I cannot force this to happen on my system, hence it is not possible for me to analyse it more in detail.