EDIT: This is actually completely wrong and I apologize. Turns out this issue is actually caused by some who miss a step in the upgrade process, of which happened with me and a few others. Follow the instructions properly and you shouldn't have this problem!!!
This is a problem I ran into soon after upgrading my Plesk Panel from 11.0.9 to 11.5. I upgraded mostly for the easy use of multiple PHP versions, and in the case of one project I needed 5.4. I followed the docs perfectly on building and all that fun stuff, but when I went to the site I got the exact same problem as described in this thread. I spent hours thinking it was with my build from source. Nope. Turns out it seems to be a bug in Plesk Panel in some upgrades to 11.5 where it turns on safe_mode which is a removed ini setting in PHP 5.4 (if any support people here could direct me to where I can either submit a bug report on this or can help with getting this fixed, that would be of great help).
If you look in /var/www/vhosts/system/<domain name>/etc/, you will see there is a generated php.ini. This file is generated each time you make a change under PHP Settings or Hosting Settings (or possibly others, I am not sure). If you look inside that and your issue is the aforementioned and you find a 'safe_mode = On' option (you can easily see if this is with 'cat php.ini | grep safe_mode'), go into PHP Settings under the domain of which you're having the issue and add 'safe_mode = Off' into Additional Directives and Save. If you load the site now it should hopefully come up without a problem. You can also see the change in that very php.ini. Note that you can also add many other options there very easily as well, such as adding extensions (I for one need Imagick).
I hope this helped some people! Sorry if it's worded poorly in some spots, I kind of typed this up in a rush.
This is a problem I ran into soon after upgrading my Plesk Panel from 11.0.9 to 11.5. I upgraded mostly for the easy use of multiple PHP versions, and in the case of one project I needed 5.4. I followed the docs perfectly on building and all that fun stuff, but when I went to the site I got the exact same problem as described in this thread. I spent hours thinking it was with my build from source. Nope. Turns out it seems to be a bug in Plesk Panel in some upgrades to 11.5 where it turns on safe_mode which is a removed ini setting in PHP 5.4 (if any support people here could direct me to where I can either submit a bug report on this or can help with getting this fixed, that would be of great help).
If you look in /var/www/vhosts/system/<domain name>/etc/, you will see there is a generated php.ini. This file is generated each time you make a change under PHP Settings or Hosting Settings (or possibly others, I am not sure). If you look inside that and your issue is the aforementioned and you find a 'safe_mode = On' option (you can easily see if this is with 'cat php.ini | grep safe_mode'), go into PHP Settings under the domain of which you're having the issue and add 'safe_mode = Off' into Additional Directives and Save. If you load the site now it should hopefully come up without a problem. You can also see the change in that very php.ini. Note that you can also add many other options there very easily as well, such as adding extensions (I for one need Imagick).
I hope this helped some people! Sorry if it's worded poorly in some spots, I kind of typed this up in a rush.
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