Error while requesting a transaction with CXEndCallAction

Question

While requesting a CXTransaction with a CXEndCallAction, the transaction fails with error code Error Domain=com.apple.CallKit.error.requesttransaction Code=4 "(null)"

I was able to make a CXStartCallAction successfully. Does anyone know what this error means?

Answer 1

The error codes for CallKit are defined in <CallKit/CXError.h>, and in iOS 10 Seed 4, error code 4 for domain com.apple.CallKit.error.requesttransaction is defined as:

CXErrorCodeRequestTransactionErrorUnknownCallUUID = 4,

This indicates that the call UUID for the requested CXEndCallAction did not correspond to an known call. I recommend confirming that the UUID set on the CXEndCallAction matches an existing call.