segfault in ntdll!RtlIntegerToUnicodeString ()

[p1plp1]

even with game paused after some hours running:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 13716.0x2398]
0x77498e19 in ntdll!RtlIntegerToUnicodeString ()
from C:\Windows\system32\ntdll.dll

backtrace:
#0 0x77498e19 in ntdll!RtlIntegerToUnicodeString ()
from C:\Windows\system32\ntdll.dll
#1 0x77498d28 in ntdll!RtlIntegerToUnicodeString ()
from C:\Windows\system32\ntdll.dll
#2 0x7343fd05 in midiOutGetID () from C:\Windows\SysWOW64\winmm.dll
#3 0x7343f05b in midiOutUnprepareHeader () from C:\Windows\SysWOW64\winmm.dll
#4 0x67a95736 in SDL2_mixer!Mix_EachSoundFont ()
from c:_visualstudio\freeserf-master\buildgw\src\SDL2_mixer.dll
#5 0x011bfce0 in ?? ()
#6 0x8b909090 in ?? ()
#7 0xdc8b53ff in ?? ()
#8 0xe4835151 in ?? ()
#9 0x04c483f8 in ?? ()
Cannot access memory at address 0x9090c361