Space bar key does no longer produce space character on screen
 

After a software/OS update my spacebar does not work anymore.
This also applies to the on screen keyboard, so it is not a hardware issue.
It happens in all applications. yesthat'swhatitlookslike ;-)
I tried downgrading some packages again, but could not find the right one.
Any helpful idas?
Thank you!

hillflyer

System: Linux Mint Tricia 19.3 Kernel: 5.4.0-64-generic x86_64 bits: 64 compiler: gcc v: 7.5.0
Desktop: MATE 1.22.2
base: Ubuntu 18.04 bionic
Machine: Type: Laptop LENOVO ThinkPad T520 with UltraNav trackpad

Hello, hillflyer & welcome to LQ.

Here's the standard thing about posting questions How_To_Ask_a_Question

Now, about your question. Borrow another keyboard and try with that. I can more easily imagine your spacebar going dodgy than I can imagine a software fault causing that not to print, and everything else be ok. Also, try it in various places and slowly.

I don't think it's hardware related since the virtual on screen keyboard produces the same error. Actually I can see the text cursor kind of twitching when I press the space bar, it just does not insert the desired space character.
Could it be related to the Ultra Nav touchpad driver?

Have you changed fonts?
Does the same happen in a code editor with a monospaced font?

As it happens with both a keyboard & an on screen keyboard, I would think it is a bad keyboard layout file in Ubuntu/Mint.

1. Run the command xev in a terminal and see what happens when you press space. The output should include
if the key is working.

2. Press Ctrl Alt F2. That will open a virtual terminal at which you will be invited to log-in. If space works there, then it's not your keyboard. To get back, use Ctrl Alt F7.

OK, this is weird: The key is working now. But I don't know WHY.
I suspect the iBus keyboard utility/driver or layout as fatmac suggested.
@ondoho: it happened everywhere also command line.
@DavidMcCann: Yes it outputsd keycode 65 now. Thanks for the XEV command and the seriously cool shortcuts!
So: THANKS guys! You made my day!
hillflyer

What DavidCann requested was not a solution, just more troubleshooting.
How did it go?