Crash on [SKTAppDelegate messageUploadCompleted] (SKTAppDelegate.m:97)

Last Exception Backtrace:
CoreFoundation                 0x00000001a62c0e38 0x1a62b7000 + 40504
libobjc.A.dylib                0x000000019f4578d4 objc_exception_throw + 56
Foundation                     0x00000001a0b6f8e8 0x1a062a000 + 5527784
UIKitCore                      0x00000001a91c7c60 0x1a848c000 + 13876320
UIKitCore                      0x00000001a91d41c8 0x1a848c000 + 13926856
UIKitCore                      0x00000001a91d448c 0x1a848c000 + 13927564
Smooch                         0x0000000108a07394 [SKTAppDelegate messageUploadCompleted] (SKTAppDelegate.m:97)
CoreFoundation                 0x00000001a62ee3b0 0x1a62b7000 + 226224
CoreFoundation                 0x00000001a6395440 0x1a62b7000 + 910400
CoreFoundation                 0x00000001a63786f0 0x1a62b7000 + 792304
CoreFoundation                 0x00000001a63029b4 _CFXNotificationPost + 700
Foundation                     0x00000001a0686d08 0x1a062a000 + 380168
Smooch                         0x0000000108a3d00c __45-[SKTConversationFetchScheduler sendMessage:]_block_invoke (SKTConversationFetchScheduler.m:209)
Smooch                         0x00000001089f68a0 __62-[SKTRemoteObjectSynchronizer queueRequest:object:completion:]_block_invoke (SKTRemoteObjectSynchronizer.m:77)
Smooch                         0x00000001089f6ce4 [SKTRemoteOperation main] (SKTRemoteOperation.m:60)