Maybe there is some way to repair this error?
Anyone?  

Mighty Gordon maybe u knw how to repair it?


Has a matter of fact any changes that i have made in overall_header.html aren't visible in code, like changing meta tags (description, keywords, title, robots, etc) for instance.

Forum works even when i have removed overall_header.html, so it is to set in a diffrent file. Where then?

OK. I've fixed this problem myself. I deleted all phpBB3 files, downloaded and uploaded to serv new ones.