Unit syntax error, not sure why

This is likely something very obvious but I can't figure it out. I'm trying to define a variable:

omega0 = e_const*hbar_const*sqrt(fermienergy/W)

fermienergy has units joules and W has units of (micro)metres. W is the thing which varies in a parametric sweep. Any ideas why it gets oranged out and says "unit syntax error"?

I'm using the radio frequency module