Object name &1 is invalid

What causes this issue?

Object name contains invalid characters, for example blank characters.
This is not allowed for the names of projects, subprojects, conversion
objects or rules

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

System Response

The corresponding object cannot be created.

How to fix this error?

Change the name of this object in such a way that it contains only valid
characters. In addition to letters and digits, only the underscore is
allowed.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.