How to change CKEditor's charset?

[seb5594]

Hello everybody!

Question is in the title. I need to change the default charset from the ckeditor, which i believe is 'utf-8'.
How would i change it to 'iso-8859-1'?

EDIT:
What i've tried so far:

1. Adding explicit charset into htaccess

2. Removing BOM of all files in "clientscript/ckeditor/".
Advised here: https://www.vbulletin.com/forum/forum/vbulletin-4/vbulletin-4-questions-problems-and-troubleshooting/398707-can-t-edit-posts?p=3621756#post3621756

3. ?

[final kaoss]

this might help you.
http://ckeditor.com/forums/Support/Change-charset-UTF-8
obviously change utf-8 to your target char set.

[seb5594]

this might help you.
http://ckeditor.com/forums/Support/Change-charset-UTF-8
obviously change utf-8 to your target char set.

I tried it but no effect at all.
My problem is pretty similar to this one:
https://www.vbulletin.com/forum/forum/vbulletin-4/vbulletin-4-questions-problems-and-troubleshooting/412168-ckeditor-choking-on-some-special-characters

But the approuch in that thread also didn't worked....
When i edit a thread with special chars and switch to ckeditor, then the textbox is empty and the console is throwing out following message:

https://vborg.vbsupport.ru/external/2017/04/15.png

Someone a idea?

[Mark.B]

403 Forbidden is a server error.

Possibly a mid_security (or other server security software) rule being triggered....you'll need to speak to your host.