E-mail address does not exist in system

What causes this issue?

You are trying to change the <ZK>Subscriptions</> settings for which the
user account needs an e-mail address configured in the system. Since
there is no e-mail address you are receiving this error message.

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?

You may either de-select the <ZK>Subscriptions</> settings or contact
the system administrator for an e-mail address configured to the user
account.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.