I faced similar issue due to local vs remote referencing
<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.3/angular.js"></script>
<script src="lib/js/ui-grid/3.0.7/ui-grid.js"></script>
As ui-grid.js is dependent on angular.js, ui-grid requires angular.js by the time its loaded. But in the above case, ui-grid.js [locally saved reference file] is loaded before angularjs was loaded [from internet],
The problem was solved if I had both angular.js and ui-grid referenced locally and as well declaring angular.js before ui-grid
<script src="lib/js/angularjs/1.4.3/angular.js"></script>
<script src="lib/js/ui-grid/3.0.7/ui-grid.js"></script>