A meeting series can not be deleted or rescheduled

I have a problem with a meeting series.

Despite meeting series ended 2 years ago it is still in calendar and cannot be deleted, canceled or rescheduled. 

I receive message: 

Unable to schedule event
Something went wrong. Edit event to try again.

Meeting was scheduled to occurs every 2 weeks between September 2021 and June of 2022. and is still in the calendar.