Pages 5.x cannot open Pages xe2x80x9908 documents. However later versions can.
Pages 6.0 for Mac (September 2016) can open documents from Pages xe2x80x9905 and later
The Apple article "Whatxe2x80x99s new in Pages for Mac" has the following entry under Pages 6.0:
- Open and edit Pages xe2x80x9905 documents. Learn more
The hyperlink goes to a page that provides more compatibility information and confirms that versions newer than Pages xe2x80x9905 can also be opened.
Pages for Mac can open
- Pages xe2x80x9905 or later
However, it can only export to Pages xe2x80x9909.
As of October 2015, Pages for iCloud can open Pages xe2x80x9906 and xe2x80x9908 documents (xe2x80x9905 support was added later)
"Pages for iCloud release notes" has the following under October 2015:
- Open Pages xe2x80x9908 and xe2x80x9906 documents.
Pages xe2x80x9905 support was added in September 2016, like with the Mac version.
iOS Pages 6.x can also open Pages xe2x80x9905 and newer
The compatibility listings for Pages 6.x says that iOS version of Pages also supports Pages xe2x80x9905 and newer. I don't know when it was added, but it is there now.