Windows Phone 8.1 - Error when synchronizing
Many users have complained that they have problems when synchronizing contacts, calendar, and e-mails via ActiveSync.
We have developed a workaround for this issue. Usually, the value for ‘Download new Content’ is set to ‘based on my usage’ by default in the settings for ActiveSync. It should now be possible to synchronize without any errors when you change these settings to manually synchronize or to automatically synchronize every hour, every 30 minutes, or every 15 minutes.