"The operation failed" when delegate accepts meeting notices

[michelle.hittenmiller]

I am trying to figure out why a user keeps getting the error "The
operation failed" when she tries to accept a meeting notice for her
manager. He has given her access to his calendar (but not his inbox)
so he will forward the notice to her but she receives the error and is
unable to accept or decline the meeting for him.

I looked through some old posts and someone was going to try removing
the delegate and then re-adding them, but it didn't say if this worked
or not. Any ideas?

Thanks in advance