Invalid argument Error after installation

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 – from a fresh download of WordPress. Make sure that you delete the old copies of files & folder before uploading the new ones.

Thanks for the quick reply but none of this will fix the problem because it is a fresh WP install.

– there are no active plugins
– re-uploading a fresh download wordpress rar-file & uploading the files again after deleting all files except the wp-content folder doesn’t work
– switching the theme back to the standart one doesn’t help (the error was also displayed before I’ve installed the theme)

Any other suggestions?

I’d still argue that you have a corrupted core file.

I think so too but what else can I do then downloading the WP 3.5 rar-file again and replace the class-wp-admin-bar.php file?

I’ve downloaded it from this source:

https://www.ads-software.com/download/

I tried the zip-file and the tar.gz-file but the error is still there!

The download is fine for me. No corrupted files. All I can suggest is that you try again.

Nothing happens after redownloading the rar-file over and over again so I just deleted the some code from line 353 from the class-wp-admin-bar.php and the error-message is gone.

Does anyone knows if this piece of code is important?

<?php foreach ( $root->children as $group ) {
$this->_render_group( $group );
} ?>

Every line in WordPress core files is important.

I have the same error after the installation!

Today I found out that the problem is caused by our server. The server is a few years old and wie tried to work with a external php.protocol that caused the errors because of a wrong or high security standart. Finally we decided to move our website to a new and more up to date server.

Maybe this information will help other ppl with the same problem!

I have found this solution
add the following code at the beginning of your wp-config.php file after <?php

ini_set(‘zend.ze1_compatibility_mode’, 0);

For me worked very well