This error occurs when the description type(%s) specified in Local modifier is not a valid one.
Check for spelling mistakes and use the right description type for the right definition.
Example
[#Menu: Gateway of Tally]
Add: Item: "My Report": Display : MyReport
[Report: MyReport]
Use : DayBook
Local: Forms: DayBook: Background: White
In the above example, the description type Forms is spelt wrong. Hence the message error T0015: The description type 'Forms' is not valid for the dynamic modifier Local.
The code is corrected by changing the description type Forms to Form.
[#Menu: Gateway of Tally]
Add: Item: "My Report": Display : MyReport
[Report: MyReport]
Use : DayBook
Local: Form: DayBook: Background: White
