Circle with Red X at start up what do I do?

[WatchBackup]

I’ve had two WD TV’s (one last year, and one this), Jeanine. Their model numbers look like this:
WDBGXT0000NBK-UESN
WDBPUF0000NBK-EESN
Underneath the WD TV unit the model number follows after the letters P/N (P/N for product number).