System seems to have issue as described here:
https://issues.freepbx.org/browse/FREEPBX-12648
GUI stops at “adding items” during backup and becomes unresponsive (phones cannot make calls).
‘service httpd restart’ restores functionality, but we are unable to backup the system.
Backup module is 13.0.27.21
All modules up to date as of Oct 22-2018
It does occasionally seem to work. Most recently in August.