Does Not Work iPhone X & iPhone 5C

[swifthublearning]

2018-01-16 13:32:31.528414+0530 RVCalendarWeekView[3113:891146] *** -[__NSCFCalendar rangeOfUnit:startDate:interval:forDate:]: date cannot be nil
Future exception.
A few of these errors are going to be reported with this complaint, then further violations will simply be ignored.
Here is the backtrace where this occurred this time (some frames may be missing due to compiler optimizations):
(
0 CoreFoundation 0x00000001820042dc + 208
1 CoreFoundation 0x0000000181ffe5c4 + 104
2 CoreFoundation 0x0000000181fff488 + 48
3 RVCalendarWeekView 0x0000000100bdbbe0 -[MSCollectionViewCalendarLayout dateForDayColumnHeaderAtIndexPath:] + 260
4 RVCalendarWeekView 0x0000000100beed40 -[MSWeekView firstDay] + 124
5 RVCalendarWeekView 0x0000000100be1290 __43-[MSWeekViewDecoratorInfinite loadNextDays]_block_invoke + 92
6 libdispatch.dylib 0x0000000100ff52cc _dispatch_call_block_and_release + 24
7 libdispatch.dylib 0x0000000100ff528c _dispatch_client_callout + 16
8 libdispatch.dylib 0x00000001010013dc _dispatch_queue_override_invoke + 984
9 libdispatch.dylib 0x00000001010069d0 _dispatch_root_queue_drain + 624
10 libdispatch.dylib 0x00000001010066f4 _dispatch_worker_thread3 + 136
11 libsystem_pthread.dylib 0x0000000181c0b06c _pthread_wqthread + 1268
12 libsystem_pthread.dylib 0x0000000181c0ab6c start_wqthread + 4
)
2018-01-16 13:32:31.530004+0530 RVCalendarWeekView[3113:891146] New days loaded: (null) - (null)
2018-01-16 13:32:31.600392+0530 RVCalendarWeekView[3113:891073] -[NSNull length]: unrecognized selector sent to instance 0x1b3284650
2018-01-16 13:32:31.600677+0530 RVCalendarWeekView[3113:891073] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSNull length]: unrecognized selector sent to instance 0x1b3284650'
*** First throw call stack:
(0x181fe6364 0x18122c528 0x181ff3828 0x181febd10 0x181ed0ecc 0x181eba168 0x100bf8d80 0x181f98858 0x181f988bc 0x181f988bc 0x181f988bc 0x181f988d4 0x181eb306c 0x181ed862c 0x100bf8d08 0x100bef720 0x100be1ba4 0x100be1ba4 0x100be1ba4 0x100be1ba4 0x100be1ba4 0x100be1ba4 0x18b63ead4 0x18b6f8254 0x100bd2a48 0x18b5f7db4 0x18b5f73cc 0x18b5f6d80 0x18b599f00 0x186029998 0x18602db20 0x185f9a36c 0x185fc1b90 0x185fc29d0 0x181f8dedc 0x181f8b894 0x181f8be50 0x181eabe58 0x183d58f84 0x18b60067c 0x100bf682c 0x1819c856c)
libc++abi.dylib: terminating with uncaught exception of type NSException