Popper launch program missing
What it means
No game of this emulator starts from the frontend.
Why it happens
Popper's default VPX script starts the program named on its SET VPXEXE line from the emulator's launch folder (PinUP documentation, VPX emulator page). VPX 10.8 installs name their 64-bit program VPinballX64.exe.
How Pincab Toolbox detects it
The launch script has exactly PinUP's default shape, and the program on its SET VPXEXE line is neither in the launch folder nor in the PATH.
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).