Situation: a long-running Plone 4.2 site does no longer display the link tool of TinyMCE . The console show some 404 errors which are possibly unrelated. In general the popup link tool looks pretty weird. This happens when we access the site over Nginx -> Varnish -> HAProxy
Opening the same site by accessing one app-server through a SSH tunel works (the link tool displays without errors) but: there is an error in plone.project.js and the overall functionality of the link tool is broken (likely related to the JS error in plone.project).
we experienced that issue in many sites running Plone 4.2 in the past and I think it had to do something with missing upgrade steps, with the <base> tag in the pages, or with both issues.
check if the tiny_mce_javascript_variables.js script is being loaded in the resource registries; if not, add it like this
Nope. This would not explain the different behavior of the same app server accessed through proxy or without proxy. And there is tiny_mce_javascript_variables.js file.?