Am getting this Exception before entering the appDelegate - ios

Question

I think it is from userDefaults, but not sure why?
-[__NSCFData _getCString:maxLength:encoding:]: unrecognized selector sent to instance 0x61100002ffc0
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFData _getCString:maxLength:encoding:]: unrecognized selector sent to instance 0x61100002ffc0'
*** First throw call stack:
(
0 CoreFoundation 0x0000000103a69d4b __exceptionPreprocess + 171
1 libobjc.A.dylib 0x0000000102fc721e objc_exception_throw + 48
2 CoreFoundation 0x0000000103ad9f04 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
3 CoreFoundation 0x00000001039ef005 ___forwarding___ + 1013
4 CoreFoundation 0x00000001039eeb88 _CF_forwarding_prep_0 + 120
5 CoreFoundation 0x00000001039a389b CFStringGetCString + 171
6 CoreFoundation 0x00000001039b377d CFLocaleCreateCanonicalLocaleIdentifierFromString + 77
7 CoreFoundation 0x00000001039b3327 _CFLocaleCopyCurrentGuts + 487
8 CoreFoundation 0x00000001039b3109 +[NSLocale currentLocale] + 9
9 Foundation 0x0000000102a8a376 -[NSUserDefaults(NSUserDefaults) init] + 1637
10 Foundation 0x0000000102a89cb5 +[NSUserDefaults(NSUserDefaults) standardUserDefaults] + 81
11 UIKit 0x00000001048098df ___UIApplicationMainPreparations_block_invoke_2 + 53
12 libclang_rt.asan_iossim_dynamic.dylib 0x0000000101d582b4 __wrap_dispatch_async_block_invoke + 260
13 libdispatch.dylib 0x00000001078e8978 _dispatch_call_block_and_release + 12
14 libdispatch.dylib 0x00000001079120cd _dispatch_client_callout + 8
15 libdispatch.dylib 0x00000001078f365f _dispatch_root_queue_drain + 1450
16 libdispatch.dylib 0x00000001078f3059 _dispatch_worker_thread3 + 123
17 libsystem_pthread.dylib 0x0000000107cbb4de _pthread_wqthread + 1129
18 libsystem_pthread.dylib 0x0000000107cb9341 start_wqthread + 13
)
libc++abi.dylib: terminating with uncaught exception of type NSException
// Storing my keys as
struct user {
static let shared = user()
let username:String = "user_username"
let password:String = "user_password"
let mobile:String = "user_mobile"
let email:String = "user_email"
let fname:String = "user_fname"
let lname:String = "user_lname"
let lastSync:String = "user_sync"
let id:String = "user_employeeId"
let empRole:String = "user_role"
let empManager:String = "user_manager"
let empFinance:String = "user_finance"
}
Thanks in Advance