The class include structure cannot be changed by transaction SNOTE/SCWB.

What causes this issue?

You have tried to change the class Include structure (local class types)
using the Note Assistant or the Correction Workbench. This operation is
not supported.

System Response

The Note Assistant or the Correction Workbench shows a red traffic light
for the class.

How to fix this error?

Implement note number 830204 in your system and manually convert the
class Include structure in Transaction SE24. For this purpose, use the
menu entry "Utilities -> Convert Local Class Types".

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.