Hi
I've had the same issue twice. The culprit seems to be a automatic restart of windows, it was that happened last time.
I could get it started again by using this workaround:
Find Enpass in start menu.
In the start menu click App settings;
Under the app settings select the "Terminate" button.
Start Enpass again from Start menu.
Long workaround: reinstall----
Hope this helps.