I've been running OS X El Capitan 10.11.6 with Windows 7 Bootcamp and Fusion 7.1.3 for the last few years without problems. I finally caved in and upgraded to macOS Catalina 10.15.4. Luckily, Bootcamp survived the process (I've had upgrades with less success), but Fusion wouldn't run Bootcamp any longer.
So I downloaded the trial version if Fusion 11.5.3, and after giving all permissions and creating a new Bootcamp VM, a UEFI loader (for lack of a better expression) starts but can't find a bootable disk. The release notes for Fusion 10 contain this remark:
For a Mac machine running on macOS 10.13, if a Windows Boot Camp partition using legacy BIOS exists on the boot disk, Fusion cannot create correct boot sector when creating a Boot Camp virtual machine from the Boot Camp partition, which causes the Boot Camp virtual machine fail to boot up.
Workaround: Check Fusion KB for detailed steps about how to workaround this issue.
I guess this is my problem, but no further clue is given, what that KB might be.
Just out of curiosity I reinstalled Fusion 7.1.3 and tried to fix the disk numbers in "Boot Camp.vmdk" manually (the upgrade to APFS seems to have renumbered the devices, it's an Apple Fusion Drive), but I get an error that a disk cannot be opened.
Is there any way to get my Bootcamp Windows running with either version of Fusion? Yes I know Windows 7 is out of support, that's not the point of my question.