Problem in Update from 2.11.2 to 2.12.1

Problem 1
WARNING:\piwik\plugins\CoreUpdater\Controller.php(53): Notice - Undefined index: latest_version_url - Piwik 2.11.2 - Please report this message in the Piwik forums: (please do a search first as it might have been reported already)

and this problem 2

Oops… there was a problem during the request. Maybe the server had a temporary issue, or maybe you requested a report with too much data. Please try again. If this error occurs repeatedly please contact your Piwik administrator for assistance.

need help >> ty (tu)

Hi there,

Thanks for the report. We will make sure this message will not dipslay in the next version.