Admin forbidden CORS error tinymce-cms

Questions
1

Silverstripe Version:5

/assets/_tinymce/tinymce-cms-xxxx.js

After upgrading to SS-5 I can log into the admin area and everything seems to work, but as soon as I try to open a page I only get to see the preview window on the right and a “Forbidden” and the left hand side is apart from the menu and headings empty. No fields to enter.

In the browser network tab I can see that it is a 403 “strict-origin-when-cross-origin” for the tinmce-cms-xxx.js file.

Locally I have no problem with it and the website runs smoothly on a test-server on a different hosting company’s server.

Has anybody any idea what might cause this? Are there any special settings somewhere on the server I have to set?

It might be related to this issue: SS4.3.0 "Forbidden" error message arises when trying to edit a page · Issue #2357 · silverstripe/silverstripe-cms · GitHub but I don’t have any files with more than one “.” although I tried this fix, but still didn’t work.

Assets folder permission is “0755”, _tinymce folder “700” and file (tinymce-cms-xxxx.js) permission “0664”. On the other server I believe is the same permission setting: asset folder: drwxrwxr-x, _tinymce folder: drwx------ and file: -rw-rw-r–

The hosting company suggested to change the permission of the _tinymce folder to 755, but that didn’t help either. As it turns out the permission get set back to 700 automatically.

Screenshot 403-console
Screenshot 403-console1055×84 4.8 KB

It might also be related to admin/pages/edit/show/ID throws 404 errors

So, what could be the reason why it works on one server and not on the other?

2

Just in case anybody else has the same issue here is the solution that worked for me:

SilverStripe\Assets\Flysystem\AssetAdapter:
  file_permissions:
    file:
      public: 0644
      private: 0644
    dir:
      public: 0755
      private: 0755

It seems this issue is around for quite some time: https://stackoverflow.com/questions/47072373/silverstripe-4-0-status-403-when-loading-tinymce.

I also found out the problem in different hosting company’s set-up.
On the server where the _tinymce works with permission 700 the “owner” and “group” are the same whereas on the other hosting server they are different.