Gary from Ai Squared repiled to my email to
support@aisquared.com with these directions which I thought I'd post here:
1. Close all applications.
2. At the ZoomText main menu, choose Help.
3. Choose Tech Support.
4. Into the FixIt command section, type AHOI and click the FixIt
button.
5. Highlight the AHOI module you wish to re-register. (Internet
Explorer)
6. Click the Remove Module button.
7. Click on the Add Module... button.
8. Highlight the appropriate module (ah_ie.dll) and click the Open
button.
9. Click the Exit button.
10. Exit and restart ZoomText.
In addition to those steps; I had to go to Internet Explorer's Tools > Manage Add-Ons > Enable Or Disable Add-Ons and re-enable the AHOI add-on (it's disabled by default for some reason which means AppReader/DocReader won't work unless it's Enabled)).
After doing that; AppReader and DocReader worked fine again.

Thanks Gary!