The active call cannot be put on hold for the purpose of consultation

What causes this issue?

In order to execute the requested action, first the active call must be
put on hold. In the process, an error occurred.
Further information on the external software component:
&V3&
The server concerned is &V1&.

System Response

The active call could not be put on hold. Therefore, the requested
follow-up action can not be executed either.

How to fix this error?

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.