When I try to access a Numbers file that I have maintained for 3 years without incident I suddenly get the message "the index.xml file is missing". What causes this and how can I retrieve the file? My back up hard drive gives me the same message.
When I try to access a Numbers file that I have maintained without incident for 3 years I now suddenly get the message "the index.xml file is missing". Beyond upgrading to Yosemite 10.10.3 and the latest Numbers upgrade I have changed nothing and I get the same message when I try to call the file up from my hard drive back up. What causes this change and how can I retrieve this file?
iMac, OS X Mountain Lion