error mivo did set player

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Cannot update for observer <NSKeyValueObservance 0x1d1977f0> for the key path "currentItem.duration" from <AVPlayer 0x1d17ca40>, most likely because the value for the key "currentItem" has changed without an appropriate KVO notification being sent. Check the KVO-compliance of the AVPlayer class.'

2017-12-14 10:18:00.021 Mivo[211:6129] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Cannot update for observer <NSKeyValueObservance 0x1d1977f0> for the key path "currentItem.duration" from <AVPlayer 0x1d17ca40>, most likely because the value for the key "currentItem" has changed without an appropriate KVO notification being sent. Check the KVO-compliance of the AVPlayer class.'
*** First throw call stack:
(0x21dfb91b 0x21596e17 0x21dfb861 0x225824bd 0x22561679 0x2254e469 0x2771f31d 0x277200af 0x2772418d 0x1b7888 0x1b7a70 0x1c234c 0x1c2294 0x1d2a9c 0x1d3ec4 0x1d19cc 0x1d2550 0x22582961 0x22582895 0x22582961 0x22582895 0x22582961 0x22561abf 0x22561717 0x2254e469 0x2771f31d 0x277200af 0x2772418d 0x1b7888 0x1b7a70 0x1b7550 0xaaf50 0x5899b7f 0x5899b6b 0x589e655 0x21dbdb6d 0x21dbc067 0x21d0b229 0x21d0b015 0x232fbac9 0x263df189 0x52154 0x219b3873)
libc++abi.dylib: terminating with uncaught exception of type NSException
warning: could not execute support code to read Objective-C class data in the process. This may reduce the quality of type information available.