ScrollHeight error when changing modes

Changed from Report to Plan then back:
"An error occurred
Please try refreshing the page, or contact your administrator / Atlassian Support if the problem continues.
Details
Exception: Uncaught TypeError: Cannot read property 'scrollHeight' of undefined
Resource: https://jira.atlassian.com/s/en_UK-tur11w-1988229788/6096/9/38fa850a70108b0a572569be5c6fd538/_/download/contextbatch/js/gh-rapid/batch.js
Line: 3668
Environment
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36"

JAC