In the previous release, after deploying a 4.0 framework web application, the runtime might have a display problem because resource files are missing. To resolve this issue, migration will update the file references in the project file.
During migration, resource file references in App_GlobalResource folder will be added to the presentation project file for 4.0 a framework web application.
If you have references to your custom resource files, make sure the references are retained after migration.