I'm using a master config file based on this one, in an MSM install of EE2 (2.5.5).
In the config file, I set the base path and url like so:
$base_url = $protocol . "://" . $_SERVER['HTTP_HOST'];
$base_path = $_SERVER['DOCUMENT_ROOT'];
This works a treat, but, I exclusively access the CP via my default site /admin - e.g. https://www.default_site.com/admin/
When I switch MSM sites in the CP, the thumbnails in my matrix file type custom fields break, because they are looking for the files in the default site rather than the MSM site I have just switched to.
Apart from accessing the CP via my other MSM site url, is there a way to get thumbnails working in this scenario? (I cannot find any config overrides specific to thumbnails, apart from the prefix value).
Note: All other file paths, file upload prefs, and front-end files work correctly - it's just the thumbnails in the CP, for the 2nd MSM site, that are broken.