Black screen in browser preview after upgrade

Black screen in browser preview after upgrade
0

After upgrading cocos creator project from 1.6.1 to 2.2.2 I’m getting a black screen on the web preview and the simulator view is freezed.

During the web preview there is no error displayed on the chrome console.

This error is shown only in the developer tools when simulator view
“[Vue warn]: Attribute “id” is ignored on component because the component is a fragment instance: http://vuejs.org/guide/components.html#Fragment-Instance

Help needed please

Keep only the assets and project.json files in the project, delete the rest of the files and try to reopen it?