SAP Message BCOMEC044 - The connected call cannot be dropped; not possible to reconnect

Diagnosis
You wanted to hang up and put the call back on hold. But an erroroccurred. You could not hang up.
Further information on the external software component:
V3
The server concerned is &V1&.

Procedure for System Administration
The error can occur in 2 different places:
1. In the connected gateway
2. In the underlying CTI software
In this case the error occurred in (&V4&).
The return code for the underlying CTI software is: &V2&