Crashes occur rarely and with no apparent reason. The issue appears to be in the UDP handling code, so disabling UDP in the connection preferences is a viable workaround.

For example below is a backtrace produced on macOSX:

Thread 24 Crashed:
    0 libnx.dylib 0x00000001005723ae GetULONG(unsigned char const*, int) + 78
    1 libnx.dylib 0x00000001005af6ea Realtime::ackMessage(int, int) + 382
    2 libnx.dylib 0x00000001005b1ea4 Realtime::read(int) + 3892
    3 libnx.dylib 0x000000010057cafd DispatchFdList::callRunnables(IoRecord const*) + 99
    4 libnx.dylib 0x000000010059da2a Dispatcher::innerLoop() + 302
    5 libnx.dylib 0x000000010059dcd8 Dispatcher::dispatch(int) + 526
    6 libnx.dylib 0x00000001005e2345 Threadable::loop(void*) + 183
    7 libsystem_pthread.dylib 0x00007fff8f866899 _pthread_body + 138
    8 libsystem_pthread.dylib 0x00007fff8f86672a _pthread_start + 137
    9 libsystem_pthread.dylib 0x00007fff8f86afc9 thread_start + 13

And another one on Linux:

#0  0x00007f722c4c3690 in GetULONG(unsigned char const*, int) () from /usr/NX/lib/libnx.so
#1  0x00007f722c4efcab in Realtime::findMessage(int, int&, int&) () from /usr/NX/lib/libnx.so
#2  0x00007f722c4f6e74 in Realtime::recoverMessage(int, int) () from /usr/NX/lib/libnx.so
#3  0x00007f722c4fbec3 in Realtime::read(int) () from /usr/NX/lib/libnx.so
#4  0x00007f722c4cb364 in DispatchFdList::callRunnables(IoRecord const*) () from /usr/NX/lib/libnx.so
#5  0x00007f722c4e3468 in Dispatcher::innerDispatch() () from /usr/NX/lib/libnx.so
#6  0x00007f722c4e4500 in Dispatcher::innerLoop() () from /usr/NX/lib/libnx.so
#7  0x00007f722c4e4728 in Dispatcher::dispatch(int) () from /usr/NX/lib/libnx.so
#8  0x00007f722c52e193 in Threadable::loop(void*) () from /usr/NX/lib/libnx.so
#9  0x00007f722d5be184 in start_thread (arg=0x7f7211010700) at pthread_create.c:312
#10 0x00007f722d2eb37d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111