Blank login page

Hi,

I have upgraded my project from 5.21.4 to 6.5.1. I have updated following widgets as per the upgrade plan:

• HTMLSnippet
• Rich Text Viewer
• Format String
• Url Redirection
• Login Form

I have deleted all the old mpk of these widgets and added new i.e updated versions. When I restart the business modeler and hit http://localhost:8080/ blank page is displayed.

When I debug using dev tools of chrome , in console i got the following exception:

mxui.js?636004617591006826:21
TypeError: Cannot read property 'insertCss' of undefined(…)

Please let me know can this be solved.