Can't open Pages documents: 'file format is invalid'

In the Finder, click on one of the documents that Pages v7.2 will not open, and press option+command+i to open a Get Info panel. What is in the Kind, Size, Created, and Modified fields? Is the document locked?

Without revealing your personal details, where is this document located: Mac boot drive, external USB storage, Microsoft OneDrive, Google Drive, DropBox, other Cloud, mounted Windows share, or mounted Linux Share?

Have you ever double-clicked these Pages documents to open them on a Windows machine, or within Google Drive?

Both the original problem document and an earlier document (2014) will only open with Pages v. 7.3. So I'm still confused, but at least I seem to be able to open the documents. Thank you.

Viking included the reason behind this behaviour—Pages documents created in or saved from Pages 5 or later do not include the index.xml file required by pages 4 (Pages '09). If you have edited these two documents, and saved (or auto-saved) the opened document, that file will now be openable (on the Mac) only by Pages 7 or later.

Regards,

Barry

The document format of Pages versions introduced after Pages '09 is not backwards compatible, and Pages '09 is letting you know it with that error dialog. Quit Pages '09, and then just double-click the same document to have it open in Pages v7.2 (7.3 if you have updated it).

With Pages '09, clicking the red traffic light in an open document only closes the document, and does not quit Pages '09. Thus, it continues running and will ambush open attempts of any .pages document. Best to follow up the red traffic light document close with a command+Q to quit the application.

I tag my Pages '09 documents with a blue tag, and known Pages v5, and later documents with a yellow tag. This visual cue prevents opening the wrong document format, and helps isolate them in Spotlight (tag:blue). If you know that a document is created by Pages '09, then right-click on it and use the Open with : Pages (4.3) menu item.

Copy and paste the following into the dialog that appears when you press shift+command+G in the FInder.

~/Library/Caches

This will drop you into the local Library Caches folder. If you have a com.apple.Iwork.pages item there, then drag and drop it into the Trash. Don't bother emptying the Trash. Close the Finder window.

Press the shift key when launching Pages, and test if you can open that reluctant document now. If it works, you may optionally skip the next paragraph, though it may be worthwhile to perform anyway.

Boot into Safe Boot mode by pressing and holding the shift key on a reboot until you see the progress bar. This will be a slower boot, and may introduce harmless graphic aberrations. Login and see if you can open the previous Pages document that you could not previously. Now, reboot normally, and test this again. You can empty the Trash now.

You are welcome.