P: Panels and filmstrip black when switching to Develop

Scott: try roll back to lightroom CC 2015.6.  I was really frustrated when I am on El Captain and updated to 2015.7 and it started to happen once in awhile.  Once rolled back I have zero black panel issues.  I am currently considering rolling back again since Adobe has failed to fix the issue in later versions (still).  If there is no crucial feature for you on 2015.7+ just roll back.  it should be really quick and your catalogue will be intact and OS un-changed.

Based on our investigation, the heart of the issue was introduced during the El Capitan updates, regardless of the Lr versions.

as it seems this is a software issue and this machine is running el cap fine, I am not sure the relevance of the  comment.

I've had no problems on a 2015 iMac after upgrading to the latest version.  Scott you can't expect them to fully support a 9 year old Mac.

not feasible on this machine at this point-early 2008 mac pro tower.  mixed reports on compatibility.  I am also in major edit print mode for a festival in 3 weeks and have 0 time to play with a new system install.  AND this issue has been happening for MANY iterations of both Lightroom and OS X.  El Cap is a very recent version and I would expect Adobe to make it work in that environment too.  Not to nitpick but  "not so much on Sierra" to me translates to still an issue with Lightroom.....  Very open to other thoughts.  It is VERY frustrating constantly (2-5x/ day) having to deal with this.  
Thanks
sp

Try update to the latest version of macOS if you can. We still heard reports of the issue occasionally on El Capitan, not so much on Sierra.

running El Cap and CC2015.10/6.10 and continue to have black panels.  way frustrating!

I will try the unfollow one again ...

yes, both of those ...

Have you tried clicking the Stop receiving notifications about this problem link at the end of the emails? Or the Unfollow button in the top right corner of this page?