I can't seem to get the Windows 10 to Windows 11 Enterprise upgrade to work in Endpoint Central no matter what ISO I try. Every single ISO I've uploaded says it's a Version Mismatch. I've downloaded the ISO straight from https://www.microsoft.com/en-us/software-download/windows11 which is linked in ManageEngine's guide. I've tried the media creation tool. I've pulled from UUP Dump and made an enterprise only ISO with 24H2 and it won't work. I do not have access to an ISO on the Volume License section of M365 nor Visual Studo subscription. However, I tested NinjaOne, Action1, Level.io, etc and they can all upgrade to Windows 11 Enterprise without the need to upload an ISO. Why does Endpoint Central need an ISO at all when so many competitors do not?

All of my Windows 11 Enterprise PCs use the generic KMS key since they're all KMS activated (KMS server managed by partner company). They show the that it's Windows 11 Enterprise, with the VOLUME_KMSCLIENT channel, with Product Key Channel Volume:GVLK.

Could this have something to do with why it always says version mismatch no matter which ISO I try?

We've tried asking ManageEngine support about this or looking at articles and all we get told is to get a different ISO file which is completely unhelpful. Are there any logs for the upgrade failing indicating what version it's seeing in Windows and what version it should be seeing?

Does anyone have any idea how to get around this?