Report error for just 1 user?

Hi, we have a user that is receiving the following error message when trying to run a report in the People Planning module. I cannot recreate the issue as an admin, it's working fine for me...

What is quite odd is that the reports worked fine for her up until a week ago.  Possible solutions we already tested: (1) Reset IIS (2) validate no changes in security (3) log out and back in.

Has anyone ever seen this before?