Half screen blue, no menu bar. Help please

Mac
#1

MBP running 10.12 I believe. No Apple icon or menu bar so I can’t confirm version or restart or shut down either.

Half the screen has a blue veil which changes sides sometimes when I click on it. At first the dock disappeared as well, but could be retrieved temporarily. It now seems to be staying in place. It is not set to ‘Hide’ in System Preferences.

I think the trigger may have been when I accidently missed clicking the right ‘Dot’ to close a Preview window.

Fortunately I had a Systems Preferences icon in the dock but I can’t find a solution that I can perform with available resources. One Apple answer is that it’s a potentially fading hard drive. Another suggests re-setting the NVRAM. I’d like to do a backup before messing around but can’t access time Machine, no menu bar.

There were several answers on-line suggesting it happens when Safari is in full-screen mode. I didn’t have Safari on; I use Firefox. I’ve never used full screen mode.

Help would be much appreciated, please.

#2

Panic averted! With no other apparent alternative I did a hard shutdown and all seems well on restart. As I don’t know exactly what caused it I want to avoid it in future so any suggestions are welcome.

#3

At one point I had an issue with the menu bar not showing up and when I right clicked on the Finder Icon in the dock, one of the options was to reset or reboot Finder or similar. It only ever showed when Finder wasn’t behaving so no idea if it still happens. I just do hard resets now if something is not doing as it should.

#4

Thanks Kyte, very useful to know for the menu bar issue. I’ll make a note of it, in a notebook, not on the computer.

Unfortunately on that occasion the Dock wasn’t visible so no Finder icon. I still don’t know why it happened.

#5

Now I dont understand. The dock was temporarily visible or it wasn’t. either way, maybe that might work next time. Although I bet you hope there wont be a next time. LOL! That said, hard resets are my goto of late.