I encountered this, again, for no apparent reason. Enpass was working fine one day. The next, I started getting this message in a tab in Chrome every time I opened a new browser. Looking in the Browser section of Enpass, where I expected to see Chrome, it's path and an "authorized" icon, I saw nothing. There appears to be no rhyme or reason to why this happens. My frustration with having to wait two business days, minimum, to get a response forced me to uninstall the app and the Chrome extension. Once that was done, I rebooted and reinstalled both. The sync to my vault happened and I authorized the browser. All is working now.
Even though I have it fixed, this seems like a prevalent enough problems that there should be more attention given to it. Uninstall/reinstall is not an exceptable long term resolution. This has been happening for a while and Enpass should get to the bottom of why the extension disappears and the connection fails.