I faced with such kind of exception during our beta package installation:
Missing Organization Feature: Tagging
Looks like Tags are enabled in Setup -> Customize -> Tags -> Tags Settings
What could be the reason?
If your app doesn't require it as a mandatory prerequisite, in your packaging Org you should not activate features in setup or refer to objects in apex.
You can see all dependencies before upload. My strategy is to work hard keeping that list close to zero. Reason is, once you have that dependency in a release, it might be very hard (sometimes even impossible) to get rid of it again.
Since you are in beta and haven't released it yet you might be able to remove the dependency by
If you can't deactivate it or can't get rid of a dependency a last resort is to migrate to a new packaging Org. This has a huge downside, since you might have to repeat an earlier security review (and pay plus wait again). So keep an eye on the dependency list before you upload a non-beta release.