Ray, I did only one thing. I put "/bookstore/iwas/index.php" (with the quotation marks) in the action field. I touched absolutely nothing else. Then, I saved and uploaded. I got the messages that I mentioned.
Then, I put a backup copy of the file (with the previous information in the action field) back into my local files and uploaded the page again. It worked.
Just to be sure, I changed ONLY the action field again. Uploaded and got the same errors.
Then, I replaced it with the backup copy, which worked.
The merchant provider is charging extra money while the site is non-compliant. How can I get the affected pages to work and be secure?