On 21 Sep 2016, at 2:07 , MartinW <wm@fastmail.fm> wrote:

Hello,

i just updated to macOS Sierra, and Pharo now starts with an empty black
window and 100% CPU load and stays like this forever.
Any ideas?

Best regards,
Martin.

It's not an "official" official release, but the following link to a new VM build was posted on Slack yesterday; two user have reported it working ("briefly" and "for several hours" respectively) on Sierra so far:
https://bintray.com/estebanlm/pharo-vm/build/201609201407#files

Cheers,
Henry