Table and runtime object & exist without DDIC reference (&)

What causes this issue?

A runtime object was found for a table that is unknown in ABAP
Dictionary. The table contains data, which is why, as a precaution, the
runtime object was not deleted.
Since there is a runtime object, this means the table was once created
in the ABAP Dictionary. The fact that the table can no longer be found
in the ABAP Dictionary could be due to the following reasons:
It is a customer-specific table which was created when the correction
system was switched off.
Depending on the history of your system, there may also be SAP tables
which were not deleted completely, or for which only the runtime object
was delivered without the related definition in the ABAP Dictionary.

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?

RESET N1
Customer-specific tables
If the table is a customer-specific table and you still need the data,
try to restore the table in ABAP Dictionary. Note the specified table
type when you do this (transparent table, pooled table, and so on).
The table may still, for example, be contained in the version database.
You can access version management under "Utilities" in ABAP Dictionary
(transaction SE11). You may also have a copy of the system that still
contains the table definition. You can also display the runtime object
and create the table according to the field names, types, and lengths
specified in the definition. You can display the runtime object in the
menu "Extras" of the database utility (transaction SE14).
Tables in the SAP namespace
Search for SAP Notes on these tables using the key words RDDNTPUR and
TG447.

Error message extract from SAP system. Copyright SAP SE.