OSH Park .kicad_pcb upload failed (KiCad 7.0.0)

I’m trying to diagnose this problem. My board passes the DRC and the zones have been filled and refilled. I uploaded the .kicad_pcb to OSH Park and the upload fails.

Failure (critical)
Sorry, we can’t process files from Kicad development builds. Please submit gerbers instead. See help page.

I know the KiCad file format has changed. Is that the issue?
I don’t want to generate the gerbers if there is actually something fundamentally wrong with my PCB.

Kicad 7 is fairly new, their system probably doesn’t support it yet.