Hello Kirk
This morning when i turned on my Mac Mini everything is fine. All the pictures have green dots. I will keep you informed if the yellow dots come back.
Thanks for all your help.
-Kim
I have one 2TB using USB 2, connected via LG 4K screen, one 2TB using USB 3, connected direct to Mac Mini and one with 4Tb using USB 3,1 connected via LG 4K screen