Unfortunately I did not find a workaround or a solution outside rescanning. I tried a few different techniques including resaving, turning on/off fast web view, but to no avail. I was surprised not to find too much information on the web about this. Let me know if you arrive at any solution or workaround.
Well, I tried breaking down the second of the files to be combined and adding it page by page to the first file, and running the accessibility check after each one. No errors until I added page 15, at which point it gave the error immediately upon importing as well as when I ran the check. In other words, it is definitely a localized problem based in one or more specific pages. I'll give more information as I proceed, but at present my best guess at a solution is to retag or replace that page.
Okay, yeah, the solution seems to be:
- Extract all the pages of the file to be added as separate files.
- Insert them one at a time, checking for errors and then saving after each success.
- When you hit one that generates an error, make a note of it, revert, and skip that page.
- Extract as a single file all the pages after the page that generated the error, and try inserting that file and see if you get an error. If so, revert and repeat steps 2-4. If not, it'll save a lot of time.
- Once you've determined the problem pages, recreate and insert those.
A potentially faster method for long documents would be to extract as a single file half the pages of the problem file, and if that half has the error, then half of those, and so on until you've narrowed it down to the right page(s).