Hi @TVappsucks
If you are using a Samsung 2017 smart TV then according to this linked help article Samsung are aware of a known issue where they can undertake a manual fix on your TV (whatever that means) by contacting Samsung UK TV support.
https://help.nowtv.com/article/app-not-loading-on-samsung-tv
turned power off at mains switch, waited 10 secs, turned on - all OK> Thanks to community member who pointed me ar this solution
Thanks. That simple solution just worked for me after spending ages trying to redownload the app.