You receive an error stating that Notes is running during the upgrade, even though the Notes client has been shutdown and is no longer running during the upgrade.
Resolving the problem
The error message appears immediately after you are prompted
to upgrade the client. It seems as though this is a timing issue, as the dialog box is given before the client has a chance to shut down completely. The dialog box does not prohibit the client from being upgraded, but it is misinforming, and creates confusion.
This issue has been reported to Quality Engineering under SPR MPGY8LYNWY, and is currently under investigation. Unfortunately, there is no known workaround at this time.