Arduino for STM32

When I try to upload the simple Blink sketch that verifies ok, I am getting this error:

Due to its file extension (or lack thereof), "C:\Users\wesbf\AppData\Local\Temp\arduino_build_245649/Blink.ino.hex" is considered as INTEL HEX format!
1821 bytes at 0x8000... Tries exceeded
An error occurred ...