Seems to be related to this question What is the '[Command Line]' that sometimes comes up when I try to quit, and how can I quickly exit it?, but the solution doesn't work for me.
I pressed esc, typed :q, <C-w> q but nothing seems to work. The window seems to capture every input and simply displays it, even mouse input!
This has happened to me a few times and everytime I forced to close the terminal. How do I go back to my work without closing vim and without closing the terminal.
It looks like some escape sequence got you into :i insert mode. Try to exit by typing <CR> + . + <CR> (a single dot on a blank line followed by enter).
:i insert mode by pressing escape. Next time it happens, I'll try the exit keys you showed and see if it helps.
– Samaursa
Mar 14 '18 at 15:16
It seems that this may be related to tmux and not vim. I'm still not sure what happens but there is some combination of keys that results in the extra console like area to appear that captures all input, no matter where it's coming from.
The solution for now is to press <C-z> to suspend vim, the only key combination I found that doesn't seem to be captured, and then type fg to bring back vim.
