更新到iOS 12之后，我的应用崩溃了。 NSUnknownKeyException是类别“ HouseAnnotation”的类别，该类别从MKAnnotation继承。有什么想法吗？
Foundation.MonoTouchException：引发Objective-C异常。名称： NSUnknownKeyException原因：NPGrid_HouseAnnotation 0x282442140 valueForUndefinedKey ::此类不符合键值编码标准 为关键字幕。本机堆栈跟踪：0 CoreFoundation 0x000000021d07ff10 + 252 1 libobjc.A.dylib 0x000000021c24da40 objc_exception_throw + 56 2 CoreFoundation 0x000000021cf97dcc + 0 3基础0x000000021da8be54 + 248 4基金会0x000000021d9ff650 + 268 5 基金会0x000000021d9ff4e4 + 268 6基金会 0x000000021daf150c + 72 7基础0x000000021daf3dc4 + 436 8基金会0x000000021daf3a44 + 464 9 基金会0x000000021da42a3c + 72 10基金会 0x000000021daee450 + 272 11 MapKit 0x000000022ddf13a4 + 100 12 MapKit 0x000000022dde9010 + 576 13 MapKit 0x000000022dde8c24 + 1088 14基础 0x000000021db305fc __NSFireTimer + 84 15 CoreFoundation 0x000000021d00ebf0 + 28 16 CoreFoundation 0x000000021d00e920 + 864 17 CoreFoundation 0x000000021d00e154 + 248 18 CoreFoundation 0x000000021d009030 + 1880 19 CoreFoundation 0x000000021d0085b8 CFRunLoopRunSpecific + 436 20图形服务 0x000000021f27c584 GSEventRunModal + 100 21 UIKitCore 0x0000000249933558 UIApplicationMain + 212 22 NPGrid 0x00000001013c27d4 _ZN7plcrash2MS5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 5264808 23 NPGrid 0x0000000101344f0c _ZN7plcrash2MS5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 4750560 24 NPGrid 0x0000000101344ecc _ZN7plcrash2MS5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 4750496 25 NPGrid 0x0000000100eee4b4 _ZN7plcrash2MS5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 201352 26 NPGrid 0x000000010129abd8 _ZN7plcrash2MS5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 4053420 27 NPGrid 0x00000001025c6298 GMSx_AbslInternalSpinLockWake + 1082452 28 NPGrid 0x000000010264abf0 GMSx_AbslInternalSpinLockWake + 1625516 29 NPGrid 0x0000000102650b38 GMSx_AbslInternalSpinLockWake + 1649908 30 NPGrid 0x00000001025a7340 GMSx_AbslInternalSpinLockWake + 955644 31 NPGrid 0x00000001027184b8 xamarin_find_protocol_wrapper_type + 28404 32 NPGrid 0x0000000100eee274 _ZN7plcrash2MS5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 200776 33 libdyld.dylib 0x000000021cac8b94 + 4