Why can't I see worker counts anymore?
I can no longer see how many workers are assigned to my extractors or how many are assigned to gather minerals. I've already reset everything back to default. I get blank boxes over my buildings where this information used to be.
I'm quite sure that there is a setting for that.
You have to go to Settings > Gameplay: it is either "Always show worker status" or "Show current order indicator".
Since I don't have SC2 installed at the moment I cannot test it. (Ignore the red box in the following screenshot).