This warning occurs when a definition is reinitialized without having an original description. %s - '%s'- Definition Type - Definition Name
Remove the reinitialization, if the definition is the original description.
Example
[#Form:Balance Sheet]
Add: Button: MyButton
[*Button: MyButton]
Here the button MyButton does not have an original description. Hence the message warning T0017: Original description is not found for Key: MyButton (Reinitialization allowed) appears.
The code is corrected by removing the reinitialization.
[#Form:Balance Sheet]
Add: Button: MyButton
[Button: MyButton]