I have found one thing that differs... The json file has a new wrapping length. The lines do not match exactly anymore even if the content still is ok. But Jenkins log says:
*SEVERE: Failed to parse C:\Jenkins_mount_point\Jenkins\updates\default.json net.sf.json.JSONException: A JSONObject text must begin with '{' at character 1 of updateCenter.post( {"connectionCheckUrl":"http://www.google.com/","core":* The entry does not give a straight answer but I assume that a special formatting like a fix line length or the like is the cause here -- You received this message because you are subscribed to the Google Groups "Jenkins Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to jenkinsci-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.