I'm trying to run a Customer Transactions report in AR but when I click on the report name in the dropdown the following error message pops up:

Unable to open data file GL fiscal years @L90AFYE, (1213)

When I click on the OK button I get this error:

Attempting to perform operation on unopened GL fiscal years file

At this point the program freezes and I have to force close it.

It's only happening with one of our subledger datasets, the other one seems to run fine. What's causing it and how do I fix it? It's never happened before...