TS1702 What to do when you get "iTunes library app not installed on iPhone; app could not be found"

Question

What to do when you get "iTunes library app not installed on iPhone; app could not be found". None of the Apple suggestions fix the problem. For example, with Animoto, one of the problem apps, I have removed it, reinstalled it, and still get the eoor message.

Answer 1

Of course.
First of all, this started when an external drive i was using died on me. I have no doubt that these apps indeed are off my system. I figure between the apps I've bought for myself and my kid, I have about 150 apps.
Now. The issue.
When I sync my iPad with iTunes on my desktop, it goes through normally until it gets to the apps. When that happens, it get an error box that reads "Some of the apps in your iTunes library were not installed on the iPad because one or more errors occurred. For a list of appps that could not be installed, click on the triangle below."
Then I get a list of apps.
(Added note to any iTunes developers out there: The titles of the apps in this list do not always match the titles of the apps in the App Store. For example, one was called "MuseumGame" on my iPad. It's called "Museum of Thieves" on the App Store. I started out with a list of 60 apps. It was a major pain to track them all down. It would be nice to have everything the same so I can use the App Store search more effectively.)
Anyway, moving on....
The error message stops my sync until I dismiss it. That, honestly, is what makes this whole thing annoying enough to seek out an answer. I can't let my iPad start syncing and walk out of the room. Yeah. I know. First World problems.
Once I dismiss the error, the sync continues and all is well.
I did the following to try to fix the problem. Mostly, I did a lot of searches:
My list of purchased apps on my iPad both using the search box and by going to every page
Searched the main App Store on my iPad using the search field. When that didn't work, I used wider searches and just scanned the page(s) for the little cloud icon that showed I had purchased the app.
I got on my desktop iTunes and searched the apps from there (without a lot of hope, but trying to be complete)
At that point, I came to the conclusion that a small number of the apps are no longer available on the App Store.
Fine. I didn't want them anyway.
I got into iTunes and went to the Apps page. None of the errant apps showed up there. I searched the iTunes help files. Nothing. I crossed my fingers, said a little prayer to the search engine gods, and tried Google. I found some things that sort of matched but they basically boiled down to "re-download the app from the App Store" or "Restore your iPad".
So I spent a couple of hours restoring my iPad. I got the error message again. I hit Google again and came up with this thread. It was as close to my problem as I found.
I think that brings us up to date.
My fundamental problem is that I seem to have found a scenario where if you have to restore apps (because, perhaps, your external drive died) and some of the apps are no longer available for download, there is an error generated that can not be permanently dismissed.
Did I miss anything important?