Error Uploading item to folder

This error message appears on each start of eM Client. Where should I look to correct the issue?

TIA… Bill

SOLVED. In eM Client, checking one of the calendars solved the problem. Sorry for the trouble.

Hi Bill, no problem, glad you’ve found a solution, let us know if you come across any other issues or questions, we’ll be happy to help.

Thank you,
Paul.