Created attachment 102328 [details] Screenshot of Kate's filesystem browser In the filesystem browser tool view, the symbol/icon that displays an arrow pointing to the left, is wrong. See attached pic.
Looks like your Breeze icon theme is missing that icon. Are you able to reproduce the issue with more recent versions of Breeze and Kate?
The problem seems to be resolved with Opensuse Leap 42.3 using plasmashell 5.8.7 and Kate 17.04.2.
Excellent.