I have had this app running for some time months and this formula has worked well for the same amount of period. But today it gives me an error. It also only sometimes gives me an error. I reload it and it is fine, then all of a sudden it gives an error.
the requested operation is invalid. Server response: Progress candidate failed: Expression expected at position 154 in 'filter((key_progCand/key_candidatesid eq 49sdfh4873443ds334sds34 or key_progCand/key_candidatesid eq d4d24d-23sdf-34-d343-34 or ))/aggregate($count as result)
the formula is this:

colBookings is a collection where I have two records listed. Progress candidates is a dataverse table.
TO give you an idea what it is for, I use it create a progress bar to showcase how far all students have progressed a course combined.

Thanks for your help!