I have the same problem. My app crashes in C3DMatrix4x4GetAffineTransforms at
0x19c811db4 <+344>: str q2, [x3].
Apparently, the address in x3 is 0.
This is my wild guess because instruction
0x19c811d20 <+196>: cbz x3, 0x19c811d28
is a "compare and branch on zero", and later, x3 is not modified before the crash.
So it seems that this is simply a bug in SceneKit, and without further information, it is hard to find a workaround.
Here is the assembler code:
SceneKit`C3DMatrix4x4GetAffineTransforms:
0x19c811c5c <+0>: fmov s4, wzr
0x19c811c60 <+4>: ldp q3, q2, [x0]
0x19c811c64 <+8>: ldp q1, q0, [x0, #0x20]
0x19c811c68 <+12>: uzp1.4s v5, v2, v2
0x19c811c6c <+16>: ext.16b v5, v5, v2, #0xc
0x19c811c70 <+20>: uzp1.4s v6, v1, v1
0x19c811c74 <+24>: ext.16b v6, v6, v1, #0xc
0x19c811c78 <+28>: fneg.4s v7, v2
0x19c811c7c <+32>: fmul.4s v6, v6, v7
0x19c811c80 <+36>: fmla.4s v6, v1, v5
0x19c811c84 <+40>: uzp1.4s v5, v6, v6
0x19c811c88 <+44>: ext.16b v5, v5, v6, #0xc
0x19c811c8c <+48>: fmul.4s v5, v3, v5
0x19c811c90 <+52>: dup.4s v6, v5[1]
0x19c811c94 <+56>: fadd.4s v6, v5, v6
0x19c811c98 <+60>: dup.4s v5, v5[2]
0x19c811c9c <+64>: fadd.4s v5, v5, v6
0x19c811ca0 <+68>: fcmp s5, #0.0
0x19c811ca4 <+72>: fmov s5, #1.00000000
0x19c811ca8 <+76>: fmov s6, #-1.00000000
0x19c811cac <+80>: fcsel s5, s6, s5, mi
0x19c811cb0 <+84>: fmul.4s v6, v3, v3
0x19c811cb4 <+88>: fmul.4s v7, v2, v2
0x19c811cb8 <+92>: zip1.2s v16, v6, v7
0x19c811cbc <+96>: zip2.2s v17, v6, v7
0x19c811cc0 <+100>: fadd.2s v16, v16, v17
0x19c811cc4 <+104>: ext.16b v7, v7, v7, #0x8
0x19c811cc8 <+108>: ext.16b v6, v6, v6, #0x8
0x19c811ccc <+112>: zip1.2s v6, v6, v7
0x19c811cd0 <+116>: fadd.2s v6, v6, v16
0x19c811cd4 <+120>: fmul.4s v7, v1, v1
0x19c811cd8 <+124>: dup.4s v16, v7[1]
0x19c811cdc <+128>: fadd.4s v16, v7, v16
0x19c811ce0 <+132>: dup.4s v7, v7[2]
0x19c811ce4 <+136>: fsqrt.2s v6, v6
0x19c811ce8 <+140>: fadd.4s v7, v7, v16
0x19c811cec <+144>: fsqrt s7, s7
0x19c811cf0 <+148>: mov.s v6[2], v7[0]
0x19c811cf4 <+152>: fmul.4s v6, v6, v5[0]
0x19c811cf8 <+156>: fcmge.4s v5, v6, #0.0
0x19c811cfc <+160>: fcmlt.4s v7, v6, #0.0
0x19c811d00 <+164>: orr.16b v5, v7, v5
0x19c811d04 <+168>: mvn.16b v5, v5
0x19c811d08 <+172>: mov.s v5[3], v5[2]
0x19c811d0c <+176>: umaxv.4s s5, v5
0x19c811d10 <+180>: cmgt.4s v4, v4, v5
0x19c811d14 <+184>: dup.4s v4, v4[0]
0x19c811d18 <+188>: movi.2d v7, #0000000000000000
0x19c811d1c <+192>: bsl.16b v4, v7, v6
0x19c811d20 <+196>: cbz x3, 0x19c811d28 ; <+204>
0x19c811d24 <+200>: str q4, [x3]
0x19c811d28 <+204>: fcmeq.4s v6, v4, #0.0
0x19c811d2c <+208>: mov.s v6[3], v6[2]
0x19c811d30 <+212>: umaxv.4s s6, v6
0x19c811d34 <+216>: fmov w8, s6
0x19c811d38 <+220>: tbnz w8, #0x1f, 0x19c811da0 ; <+324>
0x19c811d3c <+224>: fmov w8, s5
0x19c811d40 <+228>: dup.4s v5, v4[0]
0x19c811d44 <+232>: fdiv.4s v3, v3, v5
0x19c811d48 <+236>: dup.4s v5, v4[1]
0x19c811d4c <+240>: fdiv.4s v2, v2, v5
0x19c811d50 <+244>: dup.4s v4, v4[2]
0x19c811d54 <+248>: mov s6, v2[1]
0x19c811d58 <+252>: fdiv.4s v5, v1, v4
0x19c811d5c <+256>: mov s4, v5[2]
0x19c811d60 <+260>: fadd s1, s3, s6
0x19c811d64 <+264>: fadd s7, s4, s1
0x19c811d68 <+268>: fcmp s7, #0.0
0x19c811d6c <+272>: b.le 0x19c811dc0 ; <+356>
0x19c811d70 <+276>: uzp1.4s v1, v2, v5
0x19c811d74 <+280>: zip2.4s v1, v2, v1
0x19c811d78 <+284>: zip2.4s v4, v5, v3
0x19c811d7c <+288>: trn2.4s v4, v5, v4
0x19c811d80 <+292>: fsub.2s v1, v1, v4
0x19c811d84 <+296>: dup.4s v3, v3[1]
0x19c811d88 <+300>: fsub.4s v2, v3, v2
0x19c811d8c <+304>: mov.s v1[2], v2[0]
0x19c811d90 <+308>: fmov s2, #1.00000000
0x19c811d94 <+312>: fadd s4, s7, s2
0x19c811d98 <+316>: mov.s v1[3], v4[0]
0x19c811d9c <+320>: b 0x19c811e68 ; <+524>
0x19c811da0 <+324>: mov w0, #0x0
0x19c811da4 <+328>: adrp x8, 303037
0x19c811da8 <+332>: ldr x8, [x8, #0xf90]
0x19c811dac <+336>: ldr q1, [x8, #0x30]
0x19c811db0 <+340>: movi.2d v2, #0000000000000000
-> 0x19c811db4 <+344>: str q2, [x3]
0x19c811db8 <+348>: cbnz x1, 0x19c811ebc ; <+608>
0x19c811dbc <+352>: b 0x19c811ec0 ; <+612>
0x19c811dc0 <+356>: fcmp s3, s6
0x19c811dc4 <+360>: fccmp s3, s4, #0x4, gt
0x19c811dc8 <+364>: b.gt 0x19c811e0c ; <+432>
0x19c811dcc <+368>: fcmp s6, s4
0x19c811dd0 <+372>: b.le 0x19c811e44 ; <+488>
0x19c811dd4 <+376>: dup.4s v1, v3[1]
0x19c811dd8 <+380>: fadd.4s v1, v2, v1
0x19c811ddc <+384>: fmov s7, #1.00000000
0x19c811de0 <+388>: fadd s6, s6, s7
0x19c811de4 <+392>: fsub s6, s6, s3
0x19c811de8 <+396>: fsub s4, s6, s4
0x19c811dec <+400>: rev64.2s v5, v5
0x19c811df0 <+404>: zip2.4s v2, v2, v3
0x19c811df4 <+408>: fadd.2s v3, v5, v2
0x19c811df8 <+412>: fsub.2s v2, v5, v2
0x19c811dfc <+416>: mov.s v3[1], v2[1]
0x19c811e00 <+420>: mov.s v1[1], v4[0]
0x19c811e04 <+424>: mov.d v1[1], v3[0]
0x19c811e08 <+428>: b 0x19c811e68 ; <+524>
0x19c811e0c <+432>: fmov s1, #1.00000000
0x19c811e10 <+436>: fadd s1, s3, s1
0x19c811e14 <+440>: fsub s1, s1, s6
0x19c811e18 <+444>: mov.s v1[1], v3[1]
0x19c811e1c <+448>: mov.s v1[2], v3[2]
0x19c811e20 <+452>: mov.16b v3, v1
0x19c811e24 <+456>: mov.s v3[3], v2[2]
0x19c811e28 <+460>: ext.16b v5, v5, v5, #0x8
0x19c811e2c <+464>: fsub.4s v4, v3, v5
0x19c811e30 <+468>: mov.s v5[1], v2[0]
0x19c811e34 <+472>: fadd.4s v1, v1, v5
0x19c811e38 <+476>: mov.s v1[0], v4[0]
0x19c811e3c <+480>: mov.s v1[3], v4[3]
0x19c811e40 <+484>: b 0x19c811e68 ; <+524>
0x19c811e44 <+488>: zip2.4s v1, v3, v2
0x19c811e48 <+492>: fadd.2s v1, v5, v1
0x19c811e4c <+496>: fmov s5, #1.00000000
0x19c811e50 <+500>: fadd s4, s4, s5
0x19c811e54 <+504>: fsub s4, s4, s3
0x19c811e58 <+508>: mov.s v4[1], v3[1]
0x19c811e5c <+512>: rev64.2s v2, v2
0x19c811e60 <+516>: fsub.2s v4, v4, v2
0x19c811e64 <+520>: mov.d v1[1], v4[0]
0x19c811e68 <+524>: fmov s2, wzr
0x19c811e6c <+528>: fsqrt s3, s4
0x19c811e70 <+532>: fmov s4, #0.50000000
0x19c811e74 <+536>: fdiv s3, s4, s3
0x19c811e78 <+540>: fmul.4s v1, v1, v3[0]
0x19c811e7c <+544>: fcmge.4s v3, v1, #0.0
0x19c811e80 <+548>: fcmlt.4s v4, v1, #0.0
0x19c811e84 <+552>: orr.16b v3, v4, v3
0x19c811e88 <+556>: mvn.16b v3, v3
0x19c811e8c <+560>: umaxv.4s s3, v3
0x19c811e90 <+564>: cmgt.4s v2, v2, v3
0x19c811e94 <+568>: dup.4s v2, v2[0]
0x19c811e98 <+572>: adrp x9, 303037
0x19c811e9c <+576>: ldr x9, [x9, #0xf90]
0x19c811ea0 <+580>: fmov w10, s3
0x19c811ea4 <+584>: ldr q3, [x9, #0x30]
0x19c811ea8 <+588>: bit.16b v1, v3, v2
0x19c811eac <+592>: orr w8, w10, w8
0x19c811eb0 <+596>: mvn w8, w8
0x19c811eb4 <+600>: lsr w0, w8, #31
0x19c811eb8 <+604>: cbz x1, 0x19c811ec0 ; <+612>
0x19c811ebc <+608>: str q0, [x1]
0x19c811ec0 <+612>: cbz x2, 0x19c811ec8 ; <+620>
0x19c811ec4 <+616>: str q1, [x2]
0x19c811ec8 <+620>: ret