Q I have used Pages a lot, but it has sometimes refused to open some previously saved documents. A few had only just been saved, but when I tried to open them again Pages reported them as being unreadable. I have seen comments that this can result from using non-standard page sizes. Do you think that is the cause, or is OS X at fault?

A This sporadic problem has afflicted some Pages users for a while. At the moment there is no consensus as to the cause, although it looks suspiciously like an intermittent internal bug in Pages, which has been addressed in recent updates.

One way that you might be able to recover a document that has become corrupt and unusable as a result, is to delve into its contents.

Pages documents with the extension .pages are in fact Zipped archives containing several different files. To open them, rename them to have the extension .zip and decompress as if a Zip archive, for instance using Archive Utility. This will create a folder, within which is a file named index.xml that contains the text content of the document, together with a lot of XML overhead. There is also a PDF preview of the whole document that could yield useful content.

If you open a damaged document and discover that the preview is blank and there is no trace of the text content, this suggests that Pages trashed the file totally in saving that corrupt version. Your only hope then is to examine your backup copies of that document, to see if you can recover anything from them. As ever, use copies of your backups, not the originals.

Updated from the original, which was first published in MacUser volume 28 issue 07, 2012.