Hi there for info are you using Reportico as standalone ( ie not within framework like joomla,Laravel etc) and which version?? Reportico 6?
There could be memory constraints
Questions :-
How long does it run before before terminating?
Perhaps, assuming you are in standalone mode, lets start by editing the file run.php and you will two lines :-
ini_set("memory_limit", "100M");
ini_set("max_execution_time", "90);
You could perhaps try increasing these values to give more time and more memory to the process?
Let me know if that helps