Outdated, crashes on XCode 9, iPhone 8

[neilyoung]

2017-09-26 14:10:48.431168+0200 arkit-by-example[2442:1007811] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[SCNNode changeMaterial]: unrecognized selector sent to instance 0x1cc1fc900'
*** First throw call stack:
(0x184fc3d38 0x1844d8528 0x184fd11f8 0x184fc96e4 0x184eaf0dc 0x10225bc14 0x18ea5ff78 0x18ea644dc 0x18e54edc8 0x18e403748 0x18ea4e3fc 0x184f6b8b8 0x184f69270 0x184f6982c 0x184e8a2d8 0x186d1bf84 0x18e436880 0x10225e8c0 0x1849ae56c)
libc++abi.dylib: terminating with uncaught exception of type NSException