Cant accept invite to calendar: Tells me message is read only

So someone sends me a calendar invite from say Google. When i try to accept into calendar i get an error that states : “The following problem occurred when processing an imip message: Unable to save the item, because the account is read only.”
So as a test I sent invite from me own google calendar and set it so guests can modify just in case that was the issue but still get same error.
Any ideas???

Might not be the case, but the calendar could be read only. Make sure you have write permissions on that calender.

Another thing to try is to assign a default calendar for which invitations sent to the email address will be saved.

In your account settings, go to the email account on which you receive the invitations. On the General Tab, scroll down to Default Folders. Select a calendar to which you have write permissions.

Invitations sent to that email address will now be saved in that calender.

Thanks Gary. I actually have like 3 or 4 calendars. I changed to another calendar and that let me accept it.