As I said, this at least in my case was caused because I was using mutt before the sidebar was coded into the main version (I was using something called "patched" mutt). This file is not needed any more and can be removed manually and the bug is gone.
It you think this is a bug please open a bug with the information of your system with "ubuntu-bug mutt" ** Changed in: mutt (Ubuntu) Status: Confirmed => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1755755 Title: Error in Mutt sidebar when mutt is started To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutt/+bug/1755755/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs