A DNS Resolution Failure may happen if your Internet Service Provider's servers are rerouting your connection in a weird way. You can try updating your network connection to use an alternative DNS server setting to get around it, such as to Google's DNS Servers. You may also wish to contacted your ISP if this problem continues.
Edit: How you change your DNS Server Settings may vary depending on your operating system. If you are not already familiar with the process for your operating system, you can google "how to change your DNS settings <your operating system here>" to find a reliable guide as one of the top results in most cases. If you are experiencing any problems finding a guide let me know what OS you are using and I can try to find a good link for you.