LR Classic CC not syncing with Creative Cloud

[sadresser]

I'm running LR Classic CC 8.0 Build 1193777 on MacOS 10.14.1.  I've been running in this configuration for several weeks (since I upgraded to 10.14.1) and today I'm having issues with LR Classic Sync.  Sync has been working without any issue up until I noticed problems today.   I've restarted LR, restarted my Mac and verified that my LR CC non-classic (running on the same computer as LR CC classic, another laptop and an iOS device) all seem to syncing, photos taken/imported on one device show up on all others.   But LR Classic CC sync no longer works. I don't see any of these files getting synced.  The details on what I see in LR Classic CC:

The first thing I noticed was I was logged out in LR Classic CC, so I logged back in.  Several times login failed with "Lightroom has experienced an unexpected Sign In failure. Please try again later" or login has taken several minutes to login, but eventually I was able to log back in.  I then noticed that I had zero synced photos (I have ~400) so back in LR I see the sync status is "Waiting for connection".  Sometimes that goes away and sometimes it says "Syncing 3 photos".   I left LR running and came back several hours later and now I see my ~400 previously synced photos but under Lightroom>Preferences>Lightroom Sync I see "0 Uploading, 57 Downloading, 0 Pending" and its been stuck like that for 3-4 hours not making any progress.   57 is probably about the right number of outstanding photos I imported or took since my last successful sync.

Is anyone else seeing issues with LR Classic CC sync being really slow or simply not working or is there something else I should be looking at on my end?

[sadresser · Accepted solution]

I finally figured out this problem with the help of Adobe tech support. If you are a Verizon FIOS customer, read on, if not you can ignore this.

For FIOS customers the new Home Network Protection "feature" in the router could be causing your problem - it was for me.   This was released in the last few weeks and as people (like me) are enabling it and it is impacting certain connections LR CC Classic needs to have back to Adobe servers/APIs. The way I found out about it was this thread.   To see if you have this problem the computer where you have LR CC Classic installed open a browser and navigate to both of these URLs: https://api-lr.adbecrsl.com/ and https://imageup-lr.adbecrsl.com/  .

You'll probably get a browser warning first and after I navigated passed this I got a McAfee anti-virus warning page (they provide the software to Verizon for HNP).  On that page there's an option to say proceed to the site.  Once you do that for both URLs above my LR CC Classic login happened immediately after I restarted the app and my sync (particularly downloads) started working again.

In the myFios app on your phone you can also disable HNP by going to top level ... menu>Accounts&Settings>Security Settings and disable HNP.

This isn't the first problem I've had with HNP so I happily turned it off.