Upgrade RV50 to fails

I’ve been trying to upgrade my RV50 units which currently have version on them to firmware. When I select the file and upload, the upload status percentage never changes from 0% and after about a minute, I get the following change in the screen and nothing else happens. I’ve tried to go back to which I had downloaded, but get the same results. Any help would be appreciated!

Try to reload the radio firmware module first (the 4.8.1 .iso file specific to your carrier), then the upgrade might proceed.