We have a couple of sites running on the same server, during the last couple of days we've had problems with one of our sites. When loading the site instead of showing the startpage (default.aspx) the visitor is sent to http://DOMAIN/Util/login.aspx?ReturnUrl=%2fDefault.aspx this affects all visitors until an admin logs in, after that everything works as it should for a while. The windows guest account is disabled and the site had been online for about a month before this problem appeared. The site only uses EPiServer users for administration and editing. Regular visitors are either anonymous or authenticated in StarCommunity. The site runs EPiServer 4.61.0.83 and StarCommunity 2.3.0.1 however i'm unable to find any error of this sort.