Infrequently (app. 5-10 times per day), I’m getting errors from rules, e.g.
Rule 'Max/Min Temp': The name 'NULL' cannot be resolved to an item or type
Rule 'before sunset, switch on light': The name 'SunElevation' cannot be resolved to an item or type
Rule 'Max/Min Temp': The name 'Sensor_Terrace_Temperature_Max' cannot be resolved to an item or type
There does not seem to be any pattern - each of the rules is affected every now and then.
I’ve seen this error before but only under the following two circumstances:
during openHAB startup in cases where the timing works out that rules start running before everything else in openHAB has finished starting up.
the first boot after clearing the cache.
To solve 2, wait for OH to finish starting and then restart it. I’ve seen reports of two or more restarts is required. I’ve only ever needed to restart once.
To solve 1, openHABian has an option that will delay the loading of the rules until enough time has passed that everything else in openHAB has finished loading.