When internal PC users use the Chrome web browser to edit a page, users get the error
The editor didn't load this time
Browser PC: 70.0.3538.102 or greater. Unconfirmed the problem exists with older builds. Problem does not exist in Firefox or IE on the same machine.
Also the problem isn't evident in MacOS builds of Chrome: 70.0.3538.77 or 70.0.3538.102
Confluence Server version: 6.9.1 (don't judge me for not updating)
Hosted on Windows Server 2012 R2 Firewall on or off has the same effect. Unfortunately advice at: https://confluence.atlassian.com/confkb/confluence-throws-the-editor-didn-t-load-this-time-error-when-trying-to-edit-a-page-840796639.html doesn't fix the problem.
Any ideas for next steps? Users seem to greatly prefer Chrome to other web browsers so the work around is unwelcome.