Hello, madskier.

Those dialogs will pop up, often several times, whenever a bookmark is changed by a browser, either on the local or a remote Mac if you are syncing as described, if you leave Synkmark running.  You should quit Synkmark if you are not using it.  In this case, if the dialog goes away momentarily after you dismiss it, you should quit Synkmark immediately, before another one pops up.

I'm not sure from your description whether the dialog ever goes away.  If the dialog never goes away, then of course something is wrong and you need to force quit Synkmark by clicking in the Apple () menu in the upper left corner of your screen > Force Quit….  Same thing if the dialog goes away and always comes back immediately.  In either case, it may be difficult to reproduce but if you want to run our Trouble Zipper I'll see if your logs give us a clue to any bug which may need to be fixed.

If there is any pause at all between the dialogs, or if things have quieted down since you posted this message, it may indicate that Synkmark is behaving as expected, but that iCloud is syncing a lot of bookmarks for some reason, which means there may be trouble in iCloud if it doesn't stop.  If that is the case, you should run Synkmark and Pause syncing (click the Syncing button in the toolbar until it shows "!" until the iCloud issue is resolved.  You may need to clean out that iCloud.