In the current 8.3.1 release of org-mode the f/F keybinding that org-info-js provides for folding headings in plain mode (of exported html files) fails to work. Further, the 's' and 'o' keys for search and occur respectively also fail to work. Both of these work with the 8.2.10 release.
I have attached a minimal org-mode file with which I can reproduce this error. By bisecting the commit history, I find that the breaking change is introduced by commit 4ee8f4 which has the following commit message:
Author: Rasmus <address@hidden
Date: Sun Apr 19 16:00:06 2015 +0200
Revert "ox: Change label naming scheme"
This reverts commit cf7d64f1e456cad281674fc81a8074f969b7911c.
The log produced by git bisect is also attached.