WordPress – headers already sent error

Annoying problem sometimes encountered when installing WordPress software and running the installation routine:

"Warning: Cannot modify header information - headers already sent by (output started at…"

Means there is a blank line at the start or end of a php file but this is highly unlikely with a fresh WordPress install. So I think your files were corrupted when uploaded to the server. Try uploading them all again – filezilla always seems to work well.