Link to https://github.com/MatMoul/quickdial-webext/issues/105
It seem this is the same question...

Edit: Thanks for the reply...
The bug is in FVD and I can't made anything... But if you have a backup, (Previous versions on Windows or Time Machine on Mac), you can recover your storage.js in Firefox profile folder (browser-extension-data/quickdial@matmoul.com/storage.js)