Can not add bookmarks because they are being synchronised
Have recently updated my laptop to macOS Mojave and can not add bookmarks. When attempting to add a bookmark this prompt pops up: "you can't change bookmarks now because they are being synchronised wait a few minutes and try again". It's now been one week and still the same prompt pops up. Anyone have any suggestions on how to fix this?
MacBook Pro 13", macOS 10.14