Changing the key: see the notes in the long text of this message

What causes this issue?

You are setting or changing the profile parameter for the key file of
the secure storage.
Without knowing the key, it is no longer possible to read or migrate the
entries that were created with this key. This can have severe
consequences for the system, since some critical components store data
in the secure storage (such as RFC destinations or the Exchange
Infrastructure).

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

We strongly recommend that you keep the key so that you can restore it
at a later date (you can, for example, print out the file, and store it
in a secure place.)
Note also, that the dynamic change of the profile parameter is only
temporary. You need to enter this change in a profile permanently, since
otherwise the old key or the standard key will be used again when the
server is next restarted, and it will no longer be possible to read
entries that were created with the key that was temporarily active.
If you are using multiple application servers, change the parameter on
all servers within a short period of time.

Error message extract from SAP system. Copyright SAP SE.