ERR_NAME_NOT_RESOLVED error usually appears when you are trying to log on a website. When this error occurs, there is also a message telling you the web page is not available. You cannot get through this error and reach the website.
Basically, ERR_NAME_NOT_RESOLVED error results because your Internet DNS address is blocked. Typically, this has an easy solution.
1) Clear browser cookies
Browser cookies can block your Internet DNS and then cause the ERR_NAME_NOT_RESOLVED error. You can try clearing browser cookies to fix this error. Each browser has a little different method to clear your cookies, which you can search and find, if you do not already know how.
After your browser cookies are cleared, check and see if the problem is fixed.
2) Flush and renew DNS
Flushing and renewing DNS is a very good way to fix the ERR_NAME_NOT_RESOLVED error — this method is quite easy to perform and it is very effective.
a) Press Win key or click on Start Menu and then type “cmd“. Right click on Command Prompt in the result and select Run as administrator. (*Running Command Prompt as administrator is necessary!) Click on Yes when prompted to confirm your action.
b) Type the following lines. (*Hit Enter after each line of code and wait for the completion of each process, and then type the next line.)
ipconfig /flushdns
ipconfig /renew
ipconfig /registerdns
c) Close Command Prompt and restart your computer.
That is what worked for me. More details and illustrations can be found at
Easy to Fix ERR_NAME_NOT_RESOLVED Error