&1 is not a valid name for a dimension

What causes this issue?

You have specified &V1& as the name of a dimension. This name is
invalid. Specify the InfoCube name first, if this is required, and then
use F4 help.
Note that you cannot use wildcards (+,*) in the dimension name. If the
entry field for the dimension name has no mandatory entry field, leave
it empty. In this way, all dimensions for the InfoCube are examined.

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.