Instances of the class &1 cannot be created in the shared memory.

What causes this issue?

A root data class must be specified for each area. The attributes of
this class are the actual visible data of the area. This class must be
markd as "shared memory enabled" in its properties in the Class Builder.
This signals that the class is prepared for having its instances also
in the shared objects memory. However, you have specified a class that
is not marked in this way.

System Response

Error Message

How to fix this error?

Enter a root data class that is marked as "shared memory enabled" or set
this attribute in the Class Builder (SE24) for the selected class.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.