Creating default object from empty value in

Hi, its showing this error in new account activation.

When i receive the email in my mail box i click on the activation account link and this error shows in the top of the page.

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Creating default object from empty value in /home/webbadm/public_html/wp-includes/ms-settings.php on line 111
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I have made a fresh install of wordpress3.6, snapshots, domain-maping and wpmu-dev-dashboard. (yesterday)

..but also the account is activated after producing this error.

Any idea?

Thank you