Calendar Base Error

Message: Missing or wrong parameter. The event you are looking for could not be found.

Note: Please verify your URL parameter: tx_cal_controller[uid]

URL:https://www.gruene-luebeck.de/termine/cal/event/tx_cal_phpicalendar/2020/11/23/web_seminar_entgelterhoehung_in_der_pflege_endstation_armut/