Well! I will try and help as much as possible with the limited amount of data you have given us but maybe if you follow step three you could get some more data to work with :)
1) Are You using like the thread indicates truly PHPMYBITORRENT and not BT.MANAGER, because if you are using BT.Manager I would have a look ate permissions how ever I don't have either one installed at this time so I can not check if indeed that is the problem.
2) Is this problem only on that page or does it occur on other pages, the reason I ask is this can happen if you are missing a PHP lib, however I highly doubt it!
3) Turning on "
Display error messages" or add this to the offending page.
Code:
ini_set('display_errors',1); ini_set('display_startup_errors',1); error_reporting(-1);
I have never had the problem that your currently having so I need to ask if you have fiddled with the page or code linked to it.