Hi Zoran,
I've never used ng-walkthrough so I can't be of much use to you, but maybe I can give you some advice to debug the problem.
Sometimes our $log decorator gets in the middle of error reports, making it unable to know where is the error happening. In those cases I just turn it off replacing this line in core/main.js:
$provide.decorator('$log', ['$delegate', $mmLogProvider.logDecorator]);
and putting these lines instead:
$provide.decorator('$log', ['$delegate', function($log) {
$log.getInstance = function(){ return $log; };
return $log;
}]);
Sometimes you'll have to refresh several times or restart ionic serve to make it work. You'll know it works because the log entries won't have a timestamp anymore. E.g. instead of seeing:
"10/13/2015 6:10:46 PM $mmInitDelegate: Executing init process 'mmLogin'"
You'll just see:
"Executing init process 'mmLogin'"
Once you've turned the decorator off, please try to reproduce the error again. This time the error report might be more useful to you.
I hope this helps you figure out the problem!
Dani