Symptoms

The following message appears in Firefox when accessing JIRA Agile 6.6:

"Exception: TypeError: j is null
Resource: https://localhost:8080/jira/s/d41d8cd98f00b204e9800998ecf8427e-CDN/en_USc4g8e9/6332/47/a6e7ec965e52e68ee9a220d865c55c9b/_/download/contextbatch/js/jira.general/batch.js
Line: 16
Exception: TypeError: j is null
Resource: https://localhost:8080/jira/s/d41d8cd98f00b204e9800998ecf8427e-CDN/en_USc4g8e9/6332/47/a6e7ec965e52e68ee9a220d865c55c9b/_/download/contextbatch/js/jira.general/batch.js
Line: 16"

Cause

This is caused by a compatibility issue with one specific module from the script runner plugin.

Workaround

Disable the script-runner module "Displays messages to the user generated from script workflow functions(userMessageUtil)"