I did upgrades from image 40 and finally ended up with everything upgraded and Unity 8 still starting fine. So it seems it would tarball related.
The 41 details: version_detail: ubuntu=20160713,device=20160402,custom=20160713,version=41
-> custom tarball was updated from 20160623 to 20160713 -> device tarball was not updated
I did upgrades from image 40 and finally ended up with everything upgraded and Unity 8 still starting fine. So it seems it would tarball related.
The 41 details: version_detail: ubuntu= 20160713, device= 20160402, custom= 20160713, version= 41
-> custom tarball was updated from 20160623 to 20160713
-> device tarball was not updated