Gray Upload Button

Upload button grayed out. USB plugged into board but not recognized

Comrade_Max:
Upload button grayed out. USB plugged into board but not recognized

Your post is lacking detail.

Which operating system?
Which version IDE?
Which board? Original or clone? Clones often use a CH340 which needs an additional driver (under Windows at least).
Is the board recognised in Windows device manager (or Mac/Linux equivalents)?