Sync2em forbidden error

I am getting error messages when my tasks are syncronised from my Windows 7 PC to Sync2em. It says “Failed to upload”. "Item was not uploaded to CalDAV server because the server returned error: Forbidden.
It has worked previously.

this is strange - does it persist? If so, I would like to ask you couple of questions:

  1. It is your own calendar? I mean, isn’t it shared?
  2. Have you changed any settings right before it happens?


It is not happening now but it has happened before.
I didn’t change any settings.
It also kept popping up reminders despite me dismissing them or marking the tasks as 100% complete.