It looks like I forgot after the last patch update to re-authorize the Syncing Agent.  Working now, I am kipping the thread so I can run through again in the future.

Great work in reacting to the Safari Changes...!

Hello again, Matt.

I just confirmed by reading the code, and simulating Error 118747, that an occurrence of Error 118747 does not switch off syncing.  So Error 118747 is not the cause of the issue are you seeing.  Actually, Error 118747 happens once in a while, even on good days, and it's not a big deal.  That's why we don't alert and display when it happens.

So the cause must be something else.  You could continue on with the other suggestions in my previous message, but first look at something else I just thought of.  Again, open the Logs window, but this time stay in the Messages tab.  There is a filter field at the upper right.  Copy-paste or type "SMLogin" into that filter field.  The message list will narrow to show only messages containing the text "SMLogin".  They will all begin with one of these two phrases:

SMLoginItem doing ON
SMLoginItem doing OFF

SMLoginItem (It's an Apple thing) is what we use to control the on/off of our background syncing agent.  "doing ON" means that the agent is being switched ON, "doing OFF" means that the agent is being switched OFF.  Looking at the timestamps on those entries, do you see any times that the agent was switched OFF without being immediately followed by a switch ON, in other words, that it was OFF for an appreciable duration?

If that does not resolve the issue, and if you are still having this issue, run our Trouble Zipper as explained in my previous message so I can have a look at the logs and stuff myself. Whoops, I just was cleaning out email and see that you've already done that.  OK, we shall dig into your data tomorrow.

Hello, Matt.

• Make our app the active app on your Mac.
• Click in the main menu under the app's name: Logs….
• In the window that opens, click the Errors tab.
• Skim through the recent errors in the popup menu.  The short description in the top pane generally, I think, indicates if the error caused Syncing to be paused.

By default, errors which stop syncing should post a "sticky" note in the macOS Notification Center.  But it depends on how you responded to the first one.  That's too long to discuss here.  Notification Center, oh, Notification Center 

Anyhow, any interesting errors in there?  If so, and you think we should take a look, run Trouble Zipper as explained below.

Also, you might want to try watching the running of our agent process, BkmxAgent…

• Activate Finder.
• Click in the menu: Go > Utilities.
• Launch the application named "Activity Monitor".  A window will open.
• In the top right corner of the window is a text fieod for filtering results.  Type "BkmxA" into that field.  The list showld collapse to show only any "BkmxAgent" processes that are running.

If syncing is Ready or Running (the latter is when our app is quit), there should be one (and only one) BkmxAgent process indicated in Activity Monitor.  Otherwise, no BkmxAgent.  Switch Syncing back and forth between Ready and Paused a few times.  Does that work?

Move the Activity Monitor window to the bottom of the screen where you can keep an eye on it.  The only time BkmxAgent should disappear is if you launch our app and Pause or switch off Syncing.  Is it disappearing (indicating no syncing) at other times?

* * *

To send us your data with Trouble Zipper,

• Run BookMacster/Synkmark
• Click in the menu: Help ▸ Trouble Zipper
• For Question X (Extra Extension Tests), answer "No"
• For Question B (Bookmarks and Documents), answer "Don't Include Bookmarks and Documents"
• In the "Please explain..." section, tell us the time of any recent events when syncing stopped.
• Send me the resulting .zip via MailDrop, Dropbox or whatever, as instructed.