The same thing happens for me with all .m4a files. .ogg and .mp3 files are fine for example.
Linux Mint 17.3 MATE Rhythmbox version: 3.3.0-1~trustyubuntu1 0 -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to rhythmbox in Ubuntu. https://bugs.launchpad.net/bugs/1414620 Title: Rhythmbox freezes when seeking in m4a files. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/rhythmbox/+bug/1414620/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
