A link would help ... Also, when you say "mount", I assume you mean simply upload to a folder? When you say "mount", it sounds like you are setting up your own server partition, which of course then could be related.
Anyway, sounds like ini_set has been disabled for security reasons AND that you have some error reporting enabled. Try to open the file /app/parsers/slir/slir.class.php in a text editor, and locate on line 433:
$v = ini_set('memory_limit', min($estimatedMemory, SLIRConfig::$maxMemoryToAllocate) . 'M');
Change it to the following, simply with an @ in front of ini_set:
$v = @ini_set('memory_limit', min($estimatedMemory, SLIRConfig::$maxMemoryToAllocate) . 'M');
The @ symbol should prevent the error from displaying. However, I am not sure if the entire operation might still fail though, since your server is clearly incapable of running this line of code. I would like to see your X3 server diagnostics, as I have never heard of this issue before on a general shared hosting environment. Worst case scenario, you might need to hardcode a value here.