I bought pages through the app store, and apple send me a receipt but no serial number. Now pages won't save or print for me because I don't have a serial number to unlock these features. When I go into the app store application, the pages app is still listed as "installed". What should I do?
Just your Apple ID and password should work.
See: Mac App Store: Frequently Asked Questions (FAQ)
Now pages won't save or print for me because I don't have a serial number to unlock
You may need to enter your admin password in order to "unlock" files > OS X Lion: About Auto Save and Versions
Did you use a preview version of the iWork apps? Did you remove the trial version of Pages from your Mac before buying it from the Mac App Store?
If you did have a trial version and did not remove it then you need to start over. Uninsttall Pages from your Mac. You might download ind use the free AppCleaner to be sure that you get all of the pices. Restart your Mac and then download Pages again from the MAS.
http://download.cnet.com/AppCleaner/3000-2248_4-10867510.html
Need a serial number for pages!
