iOS 短视频SDK求助！！！

iOS 短视频SDK   调用视频合成方法 APP直接崩溃
确定文件目录存在


调用： [_manager exportWithTaskPath:taskPath outputPath:outputPath];


日志：

2018-11-12 16:11:15.706562+0800 ChaoRenRecruit[4195:906737] 合成参数:/var/mobile/Containers/Data/Application/0D0454E5-EEF2-4220-AC97-6C753CF535BB/Documents/com.duanqu.demo/composition/A859C2CA-F61B-4141-8D4F-E7E1F72619EF
2018-11-12 16:11:15.706593+0800 ChaoRenRecruit[4195:906737] 合成参数:/var/mobile/Containers/Data/Application/0D0454E5-EEF2-4220-AC97-6C753CF535BB/Documents/com.duanqu.demo/composition/A859C2CA-F61B-4141-8D4F-E7E1F72619EF/626F10D8-537F-448A-AD08-28E28B5144AA.mp4
1542010277414 editor_service [editor_service.cpp 3209] video layout not init
1542010277414 native_editor [native_editor.cpp 1127] SetDisplaySize message send failed. ret[268451849]
1542010277419 video_encoder [ios_hard_encoder.cpp 221] create video encoder seesion ,w 720 h 1280
1542010277446 video_encoder [ios_hard_encoder.cpp 470] AlivciOSHardEncoder::ConfigureCompressionSession, line 470, set VideoToolBox Property, mGopSize 5, mFps 25, mAvgBitRate 2800000.


1542010277446 video_encoder [video_encoder_service.cpp 374] set acceptor 0x11b6f8f90
1542010277447 audio_encoder [fdkaac_audio_encoder.cpp 98] fdkaac init channels 1, bitrate 64 format 1, sample rate 44100
[libfdk_aac @ 0x10a047400] Could not update timestamps for skipped samples.
2018-11-12 16:11:17.459705+0800 ChaoRenRecruit[4195:906737] -[NSNull length]: unrecognized selector sent to instance 0x1ee4459b0
2018-11-12 16:11:21.025027+0800 ChaoRenRecruit[4195:906737] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSNull length]: unrecognized selector sent to instance 0x1ee4459b0'
*** First throw call stack:
(0x1bdcafea0 0x1bce81a40 0x1bdbc8d04 0x1bdcb57b8 0x1bdcb745c 0x1eb3e2e64 0x1eb3e2ce4 0x1eab20070 0x1eab1ac50 0x108bef834 0x108bf3de4 0x108bc2774 0x108bf41cc 0x108bf211c 0x108bfa5c0 0x1050911e0 0x104e1ee1c 0x104e1ec60 0x1ea8ef8ec 0x1ea8effd0 0x1ea842ed8 0x1ea8578e8 0x1ea858dbc 0x1ea83afac 0x1eb356ea4 0x1c22a2c70 0x1c22a7c00 0x1c2206718 0x1c223504c 0x1c2235eb4 0x1bdc3f7a8 0x1bdc3a43c 0x1bdc3a9dc 0x1bdc3a1cc 0x1bfeb1584 0x1eaeb1054 0x104ff7a8c 0x1bd6fabb4)
libc++abi.dylib: terminating with uncaught exception of type NSException