Animated wheel left under its old name
What it means
This animated wheel (.apng) still has the table's old name, so Popper probably no longer finds it.
Why it happens
When a table is updated, Popper 1.5 renames the wheel's .png but, according to one user's report, not the .apng beside it. The animation then stays under the old name and is no longer shown. This comes from a single reported case, no official documentation confirms it.
How to fix it
Rename each .apng to the name of the .png beside it (same folder, extension .apng) if it is still the animation you want for that game. This scan renamed nothing.
How Pincab Toolbox detects it
An .apng in a Wheel folder matches no Popper game, and exactly one .png in the same folder, with the same name apart from the version number, does. The scan renamed nothing.
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. €3.99, one purchase. Run the free scan first: it confirms this is really your case.
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. Partly covered, read only: PinballX and PinballY (their settings and game lists). Not covered: Future Pinball, Pinball FX, Visual Pinball 9 and the other frontends.