You are not authorized to make changes

What causes this issue?

You have no authorization for the authorization object 'S_DEVELOP',
which would allow you to change the screen concerned.
There is also a second possibility:
You want to edit a modified SAP screen in a customer system after an
upgrate (SAP transport). The screen remains locked for editing until
the new SAP version and the customer version have been aligned
(Transaction SPAU).

System Response

Authorizations are assigned to users in profiles. Profiles are stored
in the user master record.

How to fix this error?

Comsult your system administrator.

Error message extract from SAP system. Copyright SAP SE.