Problem uploading with AVR 1.6.12

Win 10 Pro
IDE 1.6.9 and 1.6.10

With AVR board 1.6.12 programs would not upload.
Back installed to AVR 1.6.11 Things work correctly.

Don't upgrade AVR to 1.6.12 at least under Win 10

_Ernie

Yup, we've noticed. IDE 1.6.10 and AVR Boards 1.6.12 are bad.