Cannot modify tasks

[Imauny]

What Happened?

When i tried to tick off the task done, it send that message (in the photo) and i don't have a clue what to do. I believe it might have something to do with my calendar app not registering nor showing my calendar events as its supposed to.

Steps to Reproduce

Opened task to check off those already done. Then received and error message

Expected Behavior

It should tick off the already done task.

OS Version

6.x (Odin)

Software Version

Latest release (I have run all updates)

Log Output

No response

Hardware Info

No response