Canceling drag n drop dictionary Mac os 10.14.5

[9840380]

-[__NSCFString objectAtIndex:]: unrecognized selector sent to instance 0x600000f0a800 *** Canceling drag because exception 'NSInvalidArgumentException' (reason '-[__NSCFString objectAtIndex:]: unrecognized selector sent to instance 0x600000f0a800') was raised during a dragging session cert[0]: TemporalValidity =(leaf)[]> 0 cert[2]: AnchorTrusted =(leaf)[force]> 0

this link doesnt work https://pan.baidu.com/s/1cLONS1XzKMItgNLswN-mSA

Trying to built with xcode 10.2 same thing drag n drop doesnt do nothing!