When I paste text into a tmux shell running zsh by select it with a mouse and then hitting 3rd mouse button, it prefixes the text with 200~ and adds a ~ at the end.  For example, if I have the text some text marked, tmux will paste in 200~some text~ instead.I'm on Debian with tmux version 2.0 and zsh 5.1.
tmux/zsh messes up pasted text
zsh;tmux;clipboard
From zsh's READMEIncompatibilites between 5.0.8 and 5.1The default behaviour when text is pasted into an X Windows terminal  has changed significantly (unless you are using a very old terminal  emulator that doesn't support this mode).  Now, the new bracketed  paste mode treats all the pasted text as literal characters.  This  means, in particular, that a newline is simply inserted as a visible  newline; you need to hit Return on the keyboard to execute the pasted  text in one go. See the description of zle_bracketed_paste in the  zshparams manual for more.  unset zle_bracketed_paste restores the  previous behaviour.