I had a very strange experience with VirtualBox tonight.

I play with VirtualBox a lot, because it enables me to learn stuff. The strange events I refer to happened under Mageia v. 7 on an x86-64 system.

Tonight, I tried to start several of my VMs, and they would not start, complaining that they needed a 64-bit kernel, but could only see a 32-bit kernel (i686).

I mucked around for a bit, listening to some Old Time Radio mystery shows on one of my favorite OTR sites, then tried again, and the VMs started just fine.

I did nothing to my VB configuration other than just look at it, to no avail, and wait, nor did I do any system updates (I did run urpmi --auto-update and it told me that my system was up-to-date). I have used VB for years and have not encountered anything like this before.

I am well and truly kerfuffled.

Did VB experience a temporary memory blackout or what?

As far as I know that happens when the OS type is not configured correctly but that setting is separate for each VM. Since the same error occurred with different VMs I would guess something that happened to VBox Manager if that was what you were using. Otherwise maybe a disk error?