Not withstanding the trouble loading ENC's, (we will get back to that in a minute), most cruisers will be more comfortable with RNCs.
a. They "look" just like the charts you have seen/used all your life.
b. They load faster in OpenCPN.
c. NOAA updates the online charts frequently, so they are close to up-to-date always.
So, take a look at the RNCs for you cruising area, and see if you agree. You may not need or want ENCs. I use RNCs almost exclusively for real underway navigation with OpenCPN.
Now, on the failure of ENC.
May we see your logfile?
You can determine the logfile location on your system by inspecting the "help" icon on the OpenCPN toolbar. Find the logfile file, and upload it here, please.
Rick is spot on, by the way. If our documentation
is wrong or misleading, we would love to correct that in order to get new users up and running ASAP.