Calendar deleted all entries and does not allow editing

I attempted to edit a reoccurring event. Upon saving, the event duplicated every day, every option from 1969 to 20??. Now the calendar shoes no events except for this one event BUT if I search an event I know is in my calendar I can see it but can not edit it.

Is this a calendar that is synced to a cloud service (Google cal , icloud, outlook etc)? If so, can you go to your calendar on the web and edit it?