I found a video series by microsoft which explains all the access violation stuff in detail.
Most important takeaway from that:
“In general, start the debugging of a dump file by executing .exr -1, .ecxr and k. And then use !analyze -v.”
So for your C11 dump, this shows the following:
0:152> .exr -1
ExceptionAddress: 00007ffaad6029b7 (msvcp140!_Cnd_broadcast+0x0000000000000007)
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
Parameter[0]: 0000000000000000
Parameter[1]: 0000000000000018
Attempt to read from address 0000000000000018
0:152> .ecxr
rax=0000000000000000 rbx=00000009c9142c18 rcx=000000007f0bb1c0
rdx=0000000000000000 rsi=0000000000000000 rdi=000000007f0bb170
rip=00007ffaad6029b7 rsp=0000000109cdd130 rbp=0000000109cdd2a0
r8=0000000109cdd3a0 r9=0000000000000060 r10=00007ffaad6a0000
r11=00007ffaad6a15c3 r12=0000000109cdd4f0 r13=0000000000000000
r14=0000000000000000 r15=0000000000000000
iopl=0 nv up ei pl nz na po nc
cs=0033 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206
msvcp140!_Cnd_broadcast+0x7:
00007ffa`ad6029b7 488b4018 mov rax,qword ptr [rax+18h] ds:00000000`00000018=????????????????
0:152> k
*** Stack trace for last set context - .thread/.cxr resets it
*** WARNING: Unable to verify timestamp for Transient Master.vst3
*** ERROR: Module load completed but symbols could not be loaded for Transient Master.vst3
# Child-SP RetAddr Call Site
00 00000001`09cdd130 00007ffa`30b13865 msvcp140!_Cnd_broadcast+0x7 [d:\a01\_work\3\s\src\vctools\crt\github\stl\src\cond.cpp @ 92]
01 00000001`09cdd160 00000000`00000000 Transient_Master+0x4d3865
And for the C12 dump:
0:000> .exr -1
ExceptionAddress: 0000000000000000
ExceptionCode: c0000005 (Access violation)
ExceptionFlags: 00000000
NumberParameters: 2
Parameter[0]: 0000000000000008
Parameter[1]: 0000000000000000
Attempt to execute non-executable address 0000000000000000
0:000> .ecxr
rax=0000000038210010 rbx=00000000329b9950 rcx=00000000329b9950
rdx=0000000000000fa0 rsi=0000000000000000 rdi=0000000000000000
rip=0000000000000000 rsp=000000000014e368 rbp=0000000023ec7710
r8=00000001451a45e0 r9=0000000000000000 r10=00000001451a45e0
r11=8080808080808080 r12=0000000000000001 r13=0000000000000000
r14=00000000384fe260 r15=000000000fe360c8
iopl=0 nv up ei pl nz na po nc
cs=0033 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206
00000000`00000000 ?? ???
0:000> k
*** Stack trace for last set context - .thread/.cxr resets it
*** WARNING: Unable to verify timestamp for Cubase12.exe
*** ERROR: Module load completed but symbols could not be loaded for Cubase12.exe
# Child-SP RetAddr Call Site
00 00000000`0014e368 00000001`4292d922 0x0
01 00000000`0014e370 00000000`23ec73f0 Cubase12+0x292d922
02 00000000`0014e378 00000000`00000000 0x23ec73f0
Seems like the crash, as you suspected, was caused by Cubase itself…
Sometimes I wish I really learned to code low level with C and ASM… 