Seeing tmux messages easier
Using tmux is pretty slick, until something doesn't work and you want to see the error message for longer that about 750ms. That's the default setting for the messages to be displayed.
Set a new display time
For the current session
:set-option display-time <milliseconds>
So set-option display-time 4000 would set your display time to 4 seconds.
Globally
Add the -g flag.
Or add it to your tmux.conf to hold on to the configuration:
set-option -g display-time <milliseconds>
View all messages
If you want to view all the recent messages, then you can use
:show-messages
Default hot-key
<tmux-leader>~
To close out of the messages, just press <enter>.