As we announced in June, AdWords Editor versions 9.5.1 and 9.7.1 will no longer be supported after October 28, 2012. If you continue using version 9.5.1 or 9.7.1 after this date, you'll encounter errors downloading accounts, posting changes to campaign settings, or checking changes. To avoid these issues, please upgrade to the latest version (9.8.1) at your earliest convenience.
You can upgrade to version 9.8.1 through the auto-update prompt that appears when you run AdWords Editor. To preserve unposted changes and comments, select the "Backup then Upgrade" option in the prompt. You can also download the latest version from the AdWords Editor website.
For a complete list of version-specific changes, please see our release notes. To see which version you're using, go to the Help menu > About AdWords Editor (Windows) or the AdWords Editor menu > About AdWords Editor (Mac).
Posted by Andy Lutz, Inside AdWords crew