The issue might occur when using double quotes (") in the
Long description or
Short description fields under the
Help section of template items. Browsers ignore the double quote characters, and they are treated as non-escaped ones, which breaks the markup. The issue is not reproducible if double quotes are escaped like this:
\" or
".
To resolve the issue, download and install the appropriate patch available on this page:
https://github.com/SitecoreSupport/Sitecore.Support.157334/releases.
To get a solution for other XP releases, contact Sitecore Support.