Note: This is a historical reference, not a current security baseline. Magento 1 is end-of-life.

On attempt to apply SUPEE-11155 the following error reported:

checking file js/tiny_mce/plugins/media/js/media.js
Hunk #1 FAILED at 483 (different line endings).
1 out of 1 hunk FAILED

Solution

Correct line endings in js/tiny_mce/plugins/media/js/media.js from unix to dos with:
$ sed -ie 's/$/\r/' js/tiny_mce/plugins/media/js/media.js
and re-run the patch script.