Thanks for the help! Problem solved. I re-installed Postbit Tabs Lite and then disabled all plugins and products in the Product Manager before uninstalling this time. No database errors and I can still load the AdminCP page in vBulletin.
Yep. Just like it says in my first post.
Additional info...
With the product uninstalled from the Product Manager, I cannot remove the dbtech/postbittabs/hooks or dbtech/postbittabs/includes folders from the server. If I do, the AdminCP page won't load.
I downloaded and installed Profile Tabs Lite 1.1.2 for evaluation in a vBulletin 3.8.8 forum.
After uninstalling Profile Tabs Lite from the vBulletin Product Manager, I removed the Profile Tabs Lite files from the server. After doing so, I was no longer able to load the AdminCP page. IE 11...