[ubuntu] Can't delete VirtualBox snapshots

Hi.

Ubuntu 16.04.

I have a VirtualBox image that has 2 snapshots. I don't want it to have any. I want the disk to be exactly like it is when I run the VM, with the latest changes.

As I understand it I should be able to delete the two snapshots and have it be the way I want. I don't ever want to go back to those snapshots.

I can't delete the snapshots.

According to the docs, I can go to the main screen and click the snapshots button and from there delete my snapshots.

I can click the button and it appears to operate like a button (the graphic changes) but it doesn't do anything.

I found Virtual Media Manager, I can see the still-attached snapshot but when I right click on it I can't do anything.

There's an "Action" menu in the window title bar, but everything is disabled except "refresh."

Can somebody tell me what I'm missing?

Thanks.