One PHP script on website won't run

Have you tried turning on error display, or checking logs to see if it is reporting any problems?

 

Here is how I generally troubleshoot PHP scripts.

Insert die()s into the code at various points and you can see where the code's execution reaches and where it starts to hang. It's tedious when you have a large script and often you have to jump large blocks of code, then back track narrowing it down to the specific line.

Off the top of my head, I remember I once had a problem with a script working on one server but not another. After die()ing throughout the script, I was able to find a function which used a weather information feed was timing out because our Apache timeout was set too low (We had a DDOS attack the night before and dropped the timeout to help mitigate). Kinda sounds like your issue, but without actually seeing where the script dies, it's hard to diagnose.

The one drawback to my standard debug methods is it doesn't work for Zend, Ioncube, or other encoded scripts. But then again, you generally shouldn't be debugging these scripts anyways.

Hope that helps.

 

mod_security blocking?
firewalled IP of feed?
php.ini disable_fuctions blocking a command within myfeedtest.php?

Without an error message or looking at the actual code you're not going to get the answer you need. Can you use rking's suggestion and place

Code:

die("GOT TO STEP X!");

throughout your code to see how far it gets? Might give you some idea of where the code is hanging.

 

Permissions or Ownership??

Stuff like that always happen when permissions of changed either on the file or system. I find myself having to deal with that every 2 years. Check and play with the ownership and permissions of all files the script uses.