There is no context to this to even guess at what may be going on. The title says you get this error after using a docker container... The error, content of your post, and error messages say tmux...
First, please run the UbuntuForums 'system-info' script so we know what you have and a bit on how it is configured. Please post the URL of what pastebin the report gets uploaded to.
Then:
Then tell us what the Docker container was, with what application and if it ran completion(?)
The tell us what you were running in tmux terminal
Code:
tmux -V
ps -e | grep tmux