I have two questions about segmentation fault; First, how can a plugin cause a segmentation fault? Second, how to solve and fix a segmentation fault?
In PM. seg faults happen all the time. But if a seg fault occurs while a plugin is enabling or disabling, you may have to debug the plugin to norrow down to a piece of code that is causing it.
You can't really know what caused it. Sometimes it's not even PocketMine's fault, it could just be due to an error with PHP, you running out of resources, other memory related errors, etc. If you consistently get segmentation faults, try removing your plugins and using a clean PHP installation.
I once had to deal with a segfault in a fork of PM, during the php7 upgrade. What I did: -You need some linux OS for this, I recommend ubuntu. If you don't have linux anywhere use a virtual box. firstly the command strace: This may give you some information, but mostly it's not very usful. secoundly the command valgrind This helped me while getting the last C call, and i found out it was a WeakRef function call... so how to use it just enter strace/valgrind in terminal and /path/to/your/bin/php/real/binary/exectuable/file /path/to/PocketMine.php so for example: valgrind /bla/bla/bla/bin/php7/bin/php /bla/bla/bla/PocketMine.php If you get the error command not found do apt-get install valgrind/strace