Manual reboot FP2 failed

[AnotherElk]

Actually, I had some thoughts on this over here …

FP2 not rebooting after updating to 21 / Android 9

19.11.2 makes no difference according to the screenshot of @AxelS above. Else … The error message you got usually is a sign for trying to run the flash-for-windows.bat inside the ZIP file (as Windows can treat it as a folder you can operate in), you would have to unzip the ZIP file first. I hope you have a backup of all your important data before you perhaps successfully run this. It may be a downgrade at this point, and if it even works, it may require a factory reset to boot successfully. …