Possibly related to 89fc983

pathWithoutBase = pathWithoutBase.replace(/^\//, ''); on line 8 of lib/router.js resolves the issue

I'm having a similar issue - I went through and added some logging to the FlowRouter.url() function and found this output:

  var completePath = this.path.apply(this, arguments);
  // /wekan/b
  var basePath = this._basePath || '/';
  // /wekan
  var pathWithoutBase = completePath.replace(new RegExp('^' + basePath), '');
  // /b
  return Meteor.absoluteUrl(pathWithoutBase);
  // https://mydomain.net/wekan//b

The router should definitely be taking out the leading slash.

Changing line 7 of lib/router.js to

var pathWithoutBase = completePath.replace(new RegExp('^(\/)|' + basePath), '');

An argument could be added for keeping that leading slash if necessary (ie. using a hashbang).

@Serubin

var completePath = '/wekan/b';
var basePath = '/wekan';
var pathWithoutBase = completePath.replace(new RegExp('^(\/)|' + basePath), '');
Meteor.absoluteUrl(pathWithoutBase);
// "http://192.168.0.21/wekan/wekan/b"

@sunhaolin Ah, yes. Good catch, thank you.

This should fix it and account for the slash immediately following the base path if it exists.

var pathWithoutBase = completePath.replace(new RegExp('^' + basePath + '(\/)'), '');