It is possible that you'll get a message when Marvin starts up like this:
This message appears when Marvin isn't sure whether you want to sync on this computer. Normally this message will never appear! How to react to this message depends on whether you want cloud sync enabled or disabled on device.
Be sure to contact us at support to let us know this happened.
I want cloud sync enabled on this device
Simply open ☰→Settings and click to enable cloud sync.
I want cloud sync disabled on this device
You'll need to enable and then disable cloud sync in order to prevent this error message from appearing each time you start Marvin. Be sure to disable internet before turning sync on and off, or else some of your data will be synced to the cloud in the brief period while sync is enabled.