ranger does not show filepreview when in tmux

Question

I just discovered a strange behavior in my ranger-setup. When browsing through source-files with ranger (where I started ranger from within tmux) I realized that the preview-pane does not show my text-file no more.

When I browse the same sourcefile in ranger (without being in tmux) it shows the preview as expected:

What I really find interesting is, that the preview-pane itself seems to work (even under tmux), because when I browse over a tar-file, ranger lists me the contents of the tar-file in the preview-pane (or when I'm on a elf-file, the preview-pane prompts me the "FileType-Classification"). So it just does not preview plain text-files when I'm on ranger in tmux.

Has anyone an idea whats causing this issue?!

Answer 1

Finally found the problem. I haven't had the following line yet in my ~/.tmux.conf:

set-option -g default-terminal "screen-256color"

I assume that the content was displayed but I couldn't see it due to wrong color-configuration. Hope it helps someone :)