Drobo 5D in critical condition

Hi my drobo has 1 red light the rest are green and amber.
I got an email saying I have to replace one of the drives but the on the dashboard says DO NOT REMOVE any drive is the lights are green and amber.
What can I do plese help !!! I am a wedding photographer and I dont want to loose my clients wedding. !! Please help

OK - First do a full restart.

Closedown the Drobo from your Dashboard and shutdown if you can.
If not, turn off the computer, then manually turn off the Drobo.
Start your PC/Mac then your Drobo.

If you get it back make an external copy of you data.
Let us know how you get on, regardless?