File upload component displays "Migration is required" with Upload button disabled

I am running a Cuba project (version 7.2) that I have been upgrading for a while now.

I am now noticing that when I open an Edit screen that contains a File Upload component, the Upload button is disabled and has the message “Migration is required”

What could be happening ? The project started out before 7.2 and I have been upgrading since. Is it that the back-end database has old lingering values ?

upload-migration-is-required

BTW, I am using Amazon S3 file storage

Never mind. I see what was causing it. My webdav settings in Application properties was wrong. for example the webdav.server.port was not set to the correct port number and
webdav.enabled should be set to false

I am not sure what webdav has to do with uploading files to s3 but my problem is now solved.