we have a Joomla! 3.8.13 on https When I go to the article manager (default- tinymce) and try to add an image, then i see a whitescreen in the modal window. The reason is that it sends the request to http instead of https (admin uses https), so mixed content error
this is the url it sends the request to: http://url/administrator/?option=com_content&view=articles&layout=modal&tmpl=component&d33ccba6239ca044b81e08cdb65a6f71=1&editor=jform_articletext
would be grateful for a hint :) thanks
I solved this issue, the problem turned out to be non-standard .htaccess file
When clicking the image button, tinymce open an iframe thus making a request to https://url/administrator/index.php?.. and the server redirected http://url/administrator/?.. (with http and without index.php)
it then redirected back to https (as the force ssl was set in admin), but the browser already threw a mixed-content error
so changing the .htaccess to a standard joomla file fixed the issue