[xwiki-users] Can't get Export/Import to work

Using a simple XWiki 7.4.2 system I'm having problems getting Export and then Import to work. I'm want to export the entire contents of one Wiki and import it into another one. I think I'm following the instructions here correctly: http://platform.xwiki.org/xwiki/bin/view/AdminGuide/ImportExport The Export seem to go OK and generates a xar file. But when I try to Import that into a different 7.4.2 wiki (or even the one it was exported from) I get told that "No package is available for import". Tim