Hyper-V: Importing a previously-exported virtual machine sometimes results in "cannot find .vmgs file"

Question

It seems that I have a 50% success rate exporting virtual machines from Hyper-V on Windows 10 Pro.

Export always appears to function well, but sometimes importing fails.

The failure is due to Hyper-V's importing tool requiring a .vmgs file that sometimes does not exist. I'm trying to understand why some of my exported virtual machines lack this file.

When importing fails, it fails like this:

What is shown above is Hyper-V requiring this ".vmgs" file, but there is no .vmgs file in the directory, and I'm not sure why. Some of my virtual machines have this file, others do not. The ones that do import without error.

Is this file missing due to the way I'm exporting somehow? Is it supposed to be manually copied from somewhere after export? Is there a "safe" way to export such that this never occurs?