I think you’re the unfortunate finder of a regression from the most recent change: Updated ESH bundles in 2.2.0-SNAPSHOT - Important for TRADFRI users
The character it’s complaining about is a Delete char. Which is unusual, are you doing anything with HTTP in the Every 5 minutes rule?
Try clearing out the contents of /var/lib/openhab2/cache and /var/lib/openhab2/tmp