Hi, as said, if there is a fatal PHP error for some reason, it is logged on the error log of the system, there is no other way to discover it.
I can eventually try to modify the plugin on the fly to find the problematic code, I need an administrator access to do that. It will require some work, since I need to put up a simulation checking line by line the code to see when it breaks.
It can even be a memory problem: does your wp-config.php file has a WP_MEMORY_LIMIT definition?
