How can I fix this: Uncaught Error: [ensureSignedIn] no signIn route configured

I'm getting this error: Uncaught Error: [ensureSignedIn] no signIn route configured!

I can't find anything about it on google.

I have this in at the bottom of my routes.js in common code (server and client):

FlowRouter.triggers.enter([AccountsTemplates.ensureSignedIn], 
                          {except: ["templateA", "templateB"]});

Any ideas on how to fix this? I'm sure you need more information. What shall I provide to help you help me?

Additional info:

I have AccountsTemplates.configureRoute('signIn'); in the server directory. For 'fun' I decided to add it above the ensureSignedIn trigger and I got the following error:

Error: Route already configured!
    at [object Object].AccountsTemplates.configureRoute (packages/useraccounts_flow-routing.js:108:11)

That is 'funny' because without adding that line the error is that the route is NOT already configured.

The AccountsTemplates.configure and AccountsTemplates.configureRoute stuff needs to be on the client

The Accounts.emailTemplates stuff needs to be on the server.