My office is using Windows OS7 - 32 bit and Office 2010. We do not have an Exchange server and use a POP3 mail account. We began to "publish" and "share" calendars within Outlook and have been randomly receiving prompts for username and passwords for the shared calendars whenever we start Outlook. I have seen random posts on this type of error, but dated back in early Y2013 or Y2012. I have looked at clearing the cache, ghosting profiles, republishing calendars - but this doesn't work or only works temporarily. Is there a way to resolve this issue completely?