Popper media could move to another disk
What it means
PinUP Popper's media folders live on this install's own drive, while another disk with free space is available on the machine — nothing broken, just space to reclaim if you want it.
Why it happens
POPMedia/PUPVideos grow with every table and backglass added, and nothing moves them automatically — it is a decision the user makes on purpose, never made for them.
How Pincab Toolbox detects it
This install's POPMedia/PUPVideos folder(s) exist, are not already a junction, and at least one other fixed disk with free space is detected on the machine.
Automatic repair
Repair, included in the Pincab Toolbox licence, can fix this one for you. Your files are backed up first, and the fix can be undone.
Check your own pincab
Pincab Toolbox is a free Windows scanner for Visual Pinball X and PinUP Popper. It finds and explains problems like this one. No account, no telemetry.
Download for freeCovered: Visual Pinball X (10.x) and PinUP Popper. Not covered: Future Pinball, Pinball FX, Visual Pinball 9 and the other frontends (PinballX, PinballY).