Empty pagetree in TYPO3 7.2 backend

Question

I am setting up a web portal using TYPO3 version 7.2. I successfully installed TYPO3 following this article on a Red Hat 4.8.2-16 machine. Everything worked fine and I created some pages until for some reason the pagetree didn't show any content any more. So now the backend looks like this http://goo.gl/3p0uQn

My browsers debug console only returns this error:

TypeError: TYPO3ViewportInstance.DebugConsole is null   backend.php:79:5

but I have no idea if this is related to the empty pagetree. This occurs on Firefox, Chrome and IE, so I guess it has nothing to do with the browser. Also, I am logged in as an admin so it should not be due to wrong access rights.

Does anybody know what's going on there?

UPDATE: The TYPO3 Log gives me some PHP Warnings

Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /var/www/typo3_src-7.2.0/typo3/sysext/core/Classes/Http/AjaxRequestHandler.php line 255   
Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /var/www/typo3_src-7.2.0/typo3/sysext/core/Classes/Http/AjaxRequestHandler.php line 250   
Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /var/www/typo3_src-7.2.0/typo3/sysext/core/Classes/Core/Bootstrap.php line 1193
Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /var/www/typo3_src-7.2.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 439     
Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /var/www/typo3_src-7.2.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 438     
Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /var/www/typo3_src-7.2.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 425     
Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /var/www/typo3_src-7.2.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 424

UPDATE 2 Meanwhile I installed 7.2 completely fresh (even with a new database) and I still get an empty pagetree. I also tried 6.2 LTS, but also here, no pagetree. I'm beginning to think that there is a problem with my PHP settings. Im using PHP 5.6.9 and MariaDB 10.0.19.

Answer 1

Try tu put that on your php.ini :

always_populate_raw_post_data = -1

It worked for me. Have a nice day.

Raf

Answer 2

You have a PHP error somewhere. Please check your webserver log or php log for error messages. You can also show the error messages by choosing the development preset in the Install Tool or by setting the context environment variable to Development.

Make sure to clear the cache via Install Tool at least once (Important Actions).