Calendar "500" request error

I checked my calendar as normal and found an alarm icon indicating that my calendar failed to update due to a "500 error". I've tried signing out of my iCloud account and then signing back in, but that didn't resolve the issue. I've also attempted to disconnect and reconnect my iCloud account, but that didn't help either. Btw the calendar on the icloud.com website is functioning properly. I have no idea about the "500" error, please tell me what I should do.