Googling the error “BLE firmware version is not in sync with CurieBLE library” shows a few options, basically you need to match the BLE firmware with the Curie firmware, or something like that. Although in your case you want to downgrade the firmware to match. It is still done somehow via the IDE.
I don’t use the 101 so can’t really help much more, and it is definitely not a Blynk thing… I suggest you look it up in Google yourself and see if you can figure it out how to also downgrade the BLE firmware on the 101.