How to debug Security Rules

1. Look for [GENS] message, copy the path to the simulator (Database -> Rules)
2. Double-check if the path is correct (!) - is it pointing to parent or child? Add child path if necessary
3. Serialize payload with JSON.stringify(temp1, null, " ") and copy to simulator
4. Set user in simulator to the value of this.$models.user.defaultUserId
5. Check why permission was denied
6. Check if check database.rules.json makes sense (and was correctly compiled)
7. Check if check database.rules.bolt is correct

Also, see Tips.