1. Problem scene
APP startup exception crashes

BlockChainStep(1332,0x7000057ad000) malloc: * error for object 0x600000008300: pointer being freed was not allocated
* set a breakpoint in malloc_error_break to debug

Second, the cause of the crash

In Xcode8 this will occur if your image resource file has 16 bitmaps or if the image display mode is P3 and the Deployment Target is below iOS9.3. (As a matter of fact, a small button appeared in the project of our company, which caused this crash. I don’t know how the designer made this special picture…) If your App needs to support the wide color functionality, you’ll have to set the Deployment Target to above iOS9.3. If your APP doesn’t need to support wide color functionality and you want to be compatible with the older versions of iOS, you’ll need to convert all the 16-bit or P3 images to 8-bit sRGB assets

3. Solutions
Convert image to 8-bit sRGB Assets format
Reference article: Xcode assets problem caused by running iOS8 crash solution