I keep getting a " PayloadPathMismatchError" when accessing payload from the MQTT node and then passing to the String node.
I am sending flat string via MQTT a custom topic.
Any idea what that might be?
There should be a more detailed message about what exactly the problem is under that error name in the debug log. In general, though, it means the payload path is not valid due to the type of value at some point along that path in the current payload. By far the most common reason for that error is using a payload path that assumes something is an array when the value at that spot in the payload in fact not an array (or vice-versa).