For some unknown reason I am not able to access the soft proof function in the editor window
As far as I know, the only time you will or can get a grayed out Softproof which is what I believe you mean when you say, cannot access, would be if you have NO printer profile selected in Job Properties.
See screen snaps attached.
Click on the Blue Ball to the right of PRTR ICC in the first snap, and make sure there's a check in ENABLE Printer Profile, and select the correct printer profile from the list by clicking on the browse button all the way to the right of the white text box for printer profile name.
Fred