I have just downloaded 2017-07-05-raspbian-jessie.
Then used https://raw.githubusercontent.com/DexterInd/Raspbian_For_Robots/master/upd_script/fetch_grovepi.sh | bash
RPI3 booted ok without GrovePI+ plugged in, then powered down fitted GrovePi got a few green flashes on RPI, then stalled, Screen just shows Raspberries.
One thing I have found is that there may be greater power requirements, and found that older RPI power supplies could not power the RPI and GrovePi together, after using later versions of raspbian-jessie this has affected all of my RPI’s so I replaced my power supplies with the new RPI power supplies that provided a greater amp-age above 2.5amps. Which appear to have solved the power issues?
If your red led on your RPI flashes then you may need to replace its power supply.
Official Raspberry Pi International PSU with UK, Euro, US and Aus. Plugs & Inline Switch Lead – White
Sadly it did not solve the GrovePi software issue.