Alright, here's the story. It looks like the game is unable to support scouting under the following circumstances:
- you are the commissioner
- you are NOT actually the GM of a team
- you are temporarily ACTING AS the GM of a team
Note: This is only a problem if ALL of those criteria are met. For example, if you are both a commissioner AND the actual manager of a team, you can still scout with no problem. It's only when you use the "act as" drop-down to temporarily take over a team that scouting isn't supported.
Unfortunately, this is not something that can be fixed in a patch. It's just the way the game behaves. I'm sorry that we were unable to resolve this issue fully.