Login Widget No constructor found for widget LoginForm.widget.LoginForm

I have been going through the process of upgrading one of my applications from 5.15 to 6.4.1 (with 5.20 as an intermediary step). The upgrade from 5.15 to 5.20 worked without any issue. However when moving from 5.20 to 6.4.1 I am encountering some issues with the login widget. Firstly when i ran the application locally the login page would not load - only a white screen was displayed in my browser. I went back to the modeller and ran tools>check widgets. After this the page now loads but i get the following error: No constructor found for widget LoginForm.widget.LoginForm I have cleared my cache and tried multiple browsers but still get the same error. Can anyone suggest a fix?
1 answers

Did you update the login widget to the most recent version? We had this issue too but it has been fixed.

Edit: It could also be that another widget is causing this. The login widget is the one that needs to be created but this could be prevented by other JavaScript errors. You can use the break on exception function of the browser to trap the other error. Hit F12 to open the developer tools and turn it on in the sources tab.