Mandrill API problem after update to 9.12.024 (7)

I have complex blank application that ends in a Mandril template api call.
in 9.12.023 it was working fine. It no longer works in 9.12.024.

I have tried a new Mandrill api and key but still no change

I have another version of the same app/code in a different blank app that I have not generated since the update and that still works fine.

I finally recreated the same code in a new control app and it works fine and with the original api name and key.

It appears to be a problem in 9.12.024.

Regards
Doug Maclean

I reconstructed the entire App (same code!) and now works on9.12.024.