What can cause a signal 11?

Solution 1:

Signal 11 (SIGSEGV, also known as segmentation violation) means that the program accessed a memory location that was not assigned to it.

That's usually a bug in a program. So if you're writing your own program, that's the most likely cause.

It can also commonly occur with some hardware malfunctions.

Solution 2:

Please refer to segmentation fault on linux/unix