App Manager can't install apps

I uninstalled IGB from my machine and cleared preferences.

I installed a fresh copy of 9.0.1.

The apps would not install.

Then I installed 9.0.0, and checked to make sure that I could install the apps, and they installed. I closed 9.0.0.

I closed and re-opened IGB 9.0.1. Now I can install the apps in IGB 9.0.1.

It looks like the apps are accessible to 9.0.0 but not to 9.0.1, but once accessed by 9.0.0, they become available to 9.0.1.
"access" may not be the best verb here... I mean they are installable and un-installable.

I cleared my IGB preferences.

Now in 9.0.1, the apps that were installed are still installed, and cannot be uninstalled. The apps that were not installed are not installed, and cannot be installed.

To verify this a little further, I cleared preferences, opened 9.0.0, installed some apps, closed 9.0.0, opened 9.0.1. Now 9.0.1 can install/uninstalled apps.