[SOLVED] Problems with JCE Editor

Hi,
I'm having trouble with using the JCE Editor. Whenever I open a module with Custom HTML or an article, I get somezhing like the picture below.
What can I do?

Thanks in advance...

it looks like some css files are not loaded, that can happen if someone deletes them, if permission forbid access to that file does not allow that or even bad url rewriting setup can cause links not hitting their target. SO check for this things

OK, thanks for your answer.
I have checked and corrected the permissions of the template and component folder of JCE.
Still the same. I did not change anything on CSS or other settings, just added some articles to the fresh installation of hotstart.

Can you please give me some more specific hints (folders) where I can check the permissions?

Styles and scripts for administration are under /media/system/ folder

I can't understand it. Still the same.
An interesting issue is that the same thing happens after installing HD-GFonts and click on the Plugin to configure it.

I also get a blank screen, when I click on "Configuration".

I really don't understand where the problem is.

I installed the hotstart package again in a new folder.
The first thing I then did was to install JCE. The problem is still there.
It seems like there is a conlict between the template and JCE.
JCE is a very good editor and I could not find any alternative, so I want to use JCE.

Please help!