Hello, Howard.

Try this…

• In Synkmark, click in the main menu : Synkmark > Manage Browser Extensions.  In the Sync section for Chrome, click the "Test" button.  If you get a happy checkmark in a green circle, it should be (now) working.  (This step does not fix anything, but I want to ensure that you are  using the easiest and most sure-fire test.)

If the test fails,

• Quit and relaunch Chrome.
• Re-test as in the previous step.

If the test still fails,

• In Chrome, uninstall the BookMacster Sync extension, then in that Manage Browser Extensions window (re-)install it.  Be sure to click the "Test" button as instructed as the last step in the installation, and verify that you get a happy checkmark in a green circle.

Regarding why this happens, if relaunching Chrome fixed it, I believe that sometimes Chrome goes on the fritz and needs a relaunch for some extensions to work properly.  If reinstalling the extension fixed it, maybe the prior installation was not immediately followed by a "Test", which is necessary to configure the extension.

Tell us if you still have trouble after all this.