What I'm trying to do:
I have a list of training booked for technicians. As they travel to a global training centre, we try to book multiple courses back-to-back.
I'm trying to get a list of these trainings sorted by date and tech. So if a technician is going next week, he should be top of the heap but if he has more than one training, they should follow, rather than show further down the list. - Essentially I'm trying to group by technician (perCSE column).
My issue:
I create a list of unique emails and then run Get Items on each of these emails.
I'm doing this in other flows and it works just fine.
But for some reason in this flow I get the error: One or more field types are not installed properly.
perCSE is a Person field, it does not allow Groups or Multiple Selections.

This all looks as expected:

Note: As my end output, I don't want a table. I need too many columns and with the limited formatting for HTML tables, it just gets too ugly. My final output is meant to be text so I want to append the output to a string variable.
Giving up for now!
Thanks, Christine