Per these links, I seem to have to enable logging first.
- Where to find the log files -- frequent sync-conflict files
- https://docs.syncthing.net/users/faq.html#where-do-syncthing-logs-go-to
So I went on google again and this seems to be a possible way to enable logging. Assuming I am work this out, I will provide full logs if this error comes up in the next month again.