Bizarrely I can still install and uninstall 2.9.1 successfully, I'm not sure why 3.0 fails. I ran it again this morning with the switch to log and this is some of what it says:
=== Logging started: 18/03/2021 09:43:02 ===
Action 09:43:02: INSTALL.
Action start 09:43:02: INSTALL.
Action 09:43:02: SetPerMachineIfAlreadyInstalled.
Action start 09:43:02: SetPerMachineIfAlreadyInstalled.
CustomAction SetPerMachineIfAlreadyInstalled returned actual error code 1157 (note this may not be 100% accurate if translation happened inside sandbox)
Info 2898.For WixUI_Font_Normal textstyle, the system created a 'Tahoma' font, in 0 character set, of 13 pixels height.
Error 1723. There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor. Action SetPerMachineIfAlreadyInstalled, entry: SetPerMachineIfAlreadyInstalled, library: C:\Users\ADMINS~1.OMA\AppData\Local\Temp\MSI17B7.tmp
MSI (c) (D8:F0) [09:43:09:873]: Product: Enscape -- Error 1723. There is a problem with this Windows Installer package. A DLL required for this install to complete could not be run. Contact your support personnel or package vendor. Action SetPerMachineIfAlreadyInstalled, entry: SetPerMachineIfAlreadyInstalled, library: C:\Users\ADMINS~1.OMA\AppData\Local\Temp\MSI17B7.tmp
Action ended 09:43:09: SetPerMachineIfAlreadyInstalled. Return value 3.
Action 09:43:09: FatalError.
Action start 09:43:09: FatalError.
Info 2898.For WixUI_Font_Bigger textstyle, the system created a 'Tahoma' font, in 0 character set, of 19 pixels height.
Action 09:43:09: FatalError. Dialog created
Action ended 09:43:10: FatalError. Return value 2.
Action ended 09:43:10: INSTALL. Return value 3.
Property(C): UpgradeCode = {CD38131E-FA1C-4D75-8CAD-A66F1D17738F}