In item file I have:
DateTime WtrLastDate "Data ostatniego podlewania [%1$ta %1$tR]" <calendar> (Wtr)
and in a rule:
and during execution I’ve got:
201710-07 14:18:02.962 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Error during the execution of startup rule 'Watering_garden_startup': Cannot assign a value in null context.
What is wrong with rule?