User & does not exist or no address data exist for the user

What causes this issue?

You cannot execute a signature for one of the following reasons:
User ID &V1& that you have entered has not been created in the system.
The user name has not been maintained completely in user master record
&V1&. This name is copied to the signed document when you execute a
signature.

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?

Check whether you have entered the correct user ID. If it is correct,
contact your system administrator.

Procedure for System Administrators

RESET N1
Call up user master record &V1& and check whether the data for user is
correct.
<DS:TRAN.SU01>Edit User Master Record</>
Add the user's complete name on the <LS>Address</> tab page.

Error message extract from SAP system. Copyright SAP SE.