The Communications infotype (0105) must be created for person &1

What causes this issue?

The Communications infotype (0105) (subtype 0001) must be maintained
for the selected employees. The user name must also be stored in this
infotype, to ensure that the appointments calendar for this employee
can be called up.

System Response

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

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.