Dear community, I've been searching online, all day, here and elsewhere, for a solution to a couple of problems i have with a clean WordPress 3.5.1 installation. The problems are not uncommon, yet no solution mentioned in other posts has yet worked even slightly. I'm listing multiple problems in one post as they may have a common cause or at least share some context.
Installed themes are not showing up in Admin > Appearance > Themes. I can activate a theme by installing it via "Install Themes" > Search and immediately activating it. Any previously active themes become invisible. The themes work faultlessly in the frontend. No error message is displayed. Error-Log files are also clean. Reporting is set to E_ALL.
Installed themes, including the active one are not available in the Theme-Editor. Error message says:
Oops, no such file exists! Double check the name and try again, merci.
Notice: Undefined index: style.css in /is/htdocs/[path_to_wordpress_root]/wp-admin/theme-editor.php on line 64
When i upload a Media file i get an error message using the browser uploader:
Error saving media attachment.
and something similar when i use the multi-file uploader or try uploading a plugin or theme:
Missing a temporary folder.
phpinfo() shows that there is a temporary folder set (outside the ftproot that i can access). I do not have access to the php.ini. However i have added overrides/fallbacks to the wp-config.php as follows and added the folder with 777 permissions:
define( 'WP_TEMP_DIR', ABSPATH . 'wp-content/tmp' ); putenv( 'TMPDIR=/is/htdocs/[path_to_wordpress_root]/wp-content/tmp' );
Installing themes and plugins via the theme/plugin-directory-search interface (FTP) works.
I have no idea what else could be the cause of these Problems. I have repeatedly re-uploaded all WordPress files, tried previous releases (3.5) and attempted every possible file/script-ownership (webserver and regular ftp user) and a wide range of permissions from 777 to 700.
The problems persist with plugins and themes removed or reset to default.
I was able to fix another problem (CSS not loading in the admin interface) by adding this line to wp-config.php:
define('CONCATENATE_SCRIPTS', false );
No further changes have been made to the code.
This is happening on hosted webspace (HostEurope WebPack M). It is in pristine condition as it has been activated only yesterday. I have several other WordPress installations with this and other providers that work flawlessly and have been installed with less care ;-)