Illustrator CC 17.0 and 17.1 saving .ai files as Illustrator artwork files

Question

I have Illustrator CC 17.1 and when I save a file as a .ai file, it saves it as an Adobe Illustrator Artwork 17.0 file.  When I try to open the file later, I get a "file is in an unknown format and cannot be opened. "  How do I fix this?

Answer 1

inMotionNow,
If there is no solution to be found through the suggested links in the first post, you may try to go through the following list, and/or hope that one of our forum staff friends spots this thread.
The following is a general list of things you may try when the issue is not in a specific file (you may have tried/done some of them already); 1) and 2) are the easy ones for temporary strangenesses, and 3) and 4) are specifically aimed at possibly corrupt preferences); 5) is a list in itself, and 6) is the last resort.
1) Close down Illy and open again;
2) Restart the computer (you may do that up to 3 times);
3) Close down Illy and press Ctrl+Alt+Shift/Cmd+Option+Shift during startup (easy but irreversible);
4) Move the folder (follow the link with that name) with Illy closed (more tedious but also more thorough and reversible);
5) Look through and try out the relevant among the Other options (follow the link with that name, Item 7) is a list of usual suspects among other applications that may disturb and confuse Illy, Item 15) applies to CC, CS6, and maybe CS5);
Even more seriously, you may:
6) Uninstall, run the Cleaner Tool (if you have CS3/CS4/CS5/CS6/CC), and reinstall.
http://www.adobe.com/support/contact/cscleanertool.html