Sedat,
Clicking on the link it appears that you have resolved this. The site looks like it is working.
Scott
Hi there,
I've got exactly the same problem on my upgraded site! I've upgraded from 2.4 to 2.6 and everything went well but when Moodle loaded again I could see no theme/css, it looks exactly like the screenshot above.
Does anyone know how to resolve this issue and why it is caused?
Thank you in advance!
Clearing your theme cache normally "fixes" it (temporarily).
But if you can find a way to reproduce the problem and what causes it, I'd love to know.