Thread 4: EXC_BAD_ACCESS (code=1, address=0x10)

My app was working fine until just now. I have changed a few code, and tried to run the app, then it started to crash on launch. I have un-changed the code, and tried to run again, same crash keep occurring. How can I find where the cause is??

Thread 4: EXC_BAD_ACCESS (code=1, address=0x10)
 
 
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