I've been using a Ubuntu VirtualBox machine for the past couple of months. Today, I logged on as normal and started programming, but when I first logged on there was some pop-up related to VBoxGuestAdditions. I wasn't sure what that was about, so I ignored it, finished my work, and shut down the VM. The next time I went to start the VM, I got the following message while booting: FATAL: Could not read from the boot medium! System halted.
I can no longer use the VM. I've been searching various forums for help but haven't found anyone else with a similar issue where the error occurred after the VM had already been running fine for a long time. I didn't knowingly change any settings or update anything, so I'm a little baffled why my VM no longer works.
Any ideas would be greatly appreciated.