I inheriting KCSUser class as TSSUser, any sdk after 1.39.0 has this problem.

```

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Invalid type in JSON write (TSSUser)'

*** First throw call stack:

(

0   CoreFoundation                      0x000000010ec8ae65 __exceptionPreprocess + 165

1   libobjc.A.dylib                     0x000000010e703deb objc_exception_throw + 48

2   CoreFoundation                      0x000000010ec8ad9d +[NSException raise:format:] + 205

3   Foundation                          0x000000010e3f38ef _writeJSONValue + 698

4   Foundation                          0x000000010e3f754a ___writeJSONObject_block_invoke + 226

5   CoreFoundation                      0x000000010ebc2df6 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 102

6   CoreFoundation                      0x000000010ebc2cea -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 202

7   Foundation                          0x000000010e3f6cd4 _writeJSONObject + 436

8   Foundation                          0x000000010e3f37c1 _writeJSONValue + 396

9   Foundation                          0x000000010e3f35e1 -[_NSJSONWriter dataWithRootObject:options:error:] + 124

10  Foundation                          0x000000010e3f6002 +[NSJSONSerialization dataWithJSONObject:options:error:] + 333

11  Caregiver                           0x000000010a19292f -[KCSEntityPersistence updateWithEntity:route:collection:] + 511

12  Caregiver                           0x000000010a14977a -[KCSObjectCache updateObject:entity:route:collection:collectionCache:persist:] + 298

13  Caregiver                           0x000000010a14918d -[KCSObjectCache setObjects:forQuery:route:collection:persist:] + 925

14  Caregiver                           0x000000010a1030c4 -[KCSBackgroundAppdataStore cacheQuery:value:error:policy:] + 452

15  Caregiver                           0x000000010a1036d3 __87-[KCSBackgroundAppdataStore queryNetwork:withCompletionBlock:withProgressBlock:policy:]_block_invoke + 83

16  Caregiver                           0x000000010a103a3d __98-[KCSBackgroundAppdataStore queryNetwork:withCompletionBlock:withProgressBlock:policy:cacheBlock:]_block_invoke + 461

17  Caregiver                           0x000000010a0ffb1e -[KCSBackgroundAppdataStore handleLoadResponse:error:completionBlock:requestObject:] + 1470

18  Caregiver                           0x000000010a0ff48a -[KCSBackgroundAppdataStore handleLoadResponse:error:completionBlock:] + 74

19  Caregiver                           0x000000010a102d67 __84-[KCSBackgroundAppdataStore doQueryWithQuery:withCompletionBlock:withProgressBlock:]_block_invoke + 55

20  Caregiver                           0x000000010a13fcb9 -[KCSHttpRequest callCallback:request:] + 3433

21  Caregiver                           0x000000010a13e922 -[KCSHttpRequest requestCallback:request:] + 1090

22  Caregiver                           0x000000010a13e462 __23-[KCSHttpRequest start]_block_invoke_3 + 66

23  Foundation                          0x000000010e377957 __103+[__NSOperationInternal _observeValueForKeyPath:ofObject:changeKind:oldValue:newValue:indexes:context:]_block_invoke124 + 16

24  libdispatch.dylib                   0x000000010f697e5d _dispatch_call_block_and_release + 12

25  libdispatch.dylib                   0x000000010f6b849b _dispatch_client_callout + 8

26  libdispatch.dylib                   0x000000010f6a0bef _dispatch_root_queue_drain + 1829

27  libdispatch.dylib                   0x000000010f6a04c5 _dispatch_worker_thread3 + 111

28  libsystem_pthread.dylib             0x000000010f9f068f _pthread_wqthread + 1129

29  libsystem_pthread.dylib             0x000000010f9ee365 start_wqthread + 13

)

libc++abi.dylib: terminating with uncaught exception of type NSException

```