This is an ongoing issue with GIFTS Online, and it applies whenever you have a dashboard part that displays your reports. Luckily, the error doesn't prevent anything from working, and the simplest workaround is to simply click the 'OK' button every time you login.

You can additionally remove the dashboard part that displays your reports, and this will also resolve the issue.

We are working to fix this permanently, and we appreciate your patience in the meantime.