Can't install FreePBX 13

What is required for the installer to be able to talk to Asterisk over the Manager connection? I’ve made no changes to my installation scripts (which follow the Debian instructions on your Wiki) in several months which built a working FreePBX 13/Asterisk 13 until a week or so ago, but there have been many updates to FreePBX 13 and Debian packages, I would appreciate some assistance with determining where a previously working Manager connection apparently has broken down.