I just finished setting up two GLPI servers and had the same issue on both. After much slogging though google with very little help, I found mention of ownership issues (not to be confused with permissions issues). The glpi folder and all files and subfolders must be owned by the user and group the web server is running as. (Typically “nobody”, “www-data”, or “apache”.) It doesn’t matter even if you set your permissions chmod 777, the ownership is what makes the difference.

Assuming your httpd’s user/group is www-data here’s what you need to do: (Bold is a command, regular is the output, highlights are added for emphasis.)

htdocs # ls -l
total 2
drwxrwxrwx 15 root root 4096 Nov 30 06:04 glpi
-rw-r–r– 1 root root 44 Nov 20 15:22 index.html
htdocs# chown -R www-data:www-data glpi
htdocs # ls -l
total 2
drwxrwxrwx 15 www-data www-data 4096 Nov 30 06:04 glpi
-rw-r–r– 1 root root 44 Nov 20 15:22 index.html