Some bookmarks refer to pages which are not in the pageMap (the pageMap holds the object number and generation number for each page in the PDF). This was because the pageMap had the wrong objects. If the catalog had a list of page references, they were handled properly. If it had a list of lists of page references, it was also handled properly, but anything beyond that failed. In my previous testing I didn't come across this case, but I have now and I've confirmed that it works correctly. Unfortunately, I can't provide the PDF which demonstrates the problem before the patch is applied and confirms that the patch solves the problem on account of confidential data in the document.