Have you tried:
– deactivating all plugins to see if this resolves the problem. If this works, re-activate the plugins one by one until you find the problematic plugin(s).
– switching to the default theme to rule out any theme-specific problems.
– resetting the plugins folder by FTP or PhpMyAdmin. Sometimes, an apparently inactive plugin can still cause problems.
– re-uploading all files & folders – except the wp-content folder and wp-config.php & root .htaccess files – from a fresh download of WordPress. Make sure that you delete the old copies of files & folder before uploading the new ones.
dear esmi, many thanks for your help.
I’ve set up a complete new installation and to make sure I really didn’t change anything in prior, I just swiped my webspace again and did nothing else then installing th wordpress 3.8. via parallels automation upragded to 3.8.1 via the WP backend, went to appearance => Header and tried changing the BG-Image of the default theme. The problem remains the same. I can choose an image (http://mywebsite/wp-admin/themes.php?page=custom-header&step=2&_wpnonce-custom-header-upload=743ebcfb7b&file=6) and when I click “crop and publish” I am landing on the themes overview (http://mywebsite/wp-admin/themes.php?step=3)
Is it a server configuration problem? PHP Version? File Permission? Any further idea?
Many thanks
Try re-uploading all files & folders from a fresh download of WordPress. Make sure that you delete the old copies of files & folder before uploading the new ones.
Sorry is there no other way? I mean are you recommending me in the next step to set up a new server? It is a complete fresh installation made out of plesk! what could be wrong?
are you recommending me in the next step to set up a new server?
No – I am simply suggesting that you upload a fresh set of WordPress files.
Dear all, after I’ve seen no other opportunity, I did manually download the latest Version of WordPress and installed it on my server. And the problem remains exactly the same as when Plesk downloads and installs the latest version for me!
Does anybody have an idea why I can’t set my header image?