Why am I getting "Can not find that web page" errors so often since installing my R6400 router?

Netgear released bad firmware. 

All I see is a blank message. Is there supposed to be something more than the title, which seems to be chopped off at the end.

You can help people to help you by providing the information suggested in this forum's header:

Subject (Include model number and brief summary)
Model (Recommended - Helps the community give the best answers)
Body (Include additional detail including model version, firmware, OS and environment where relevant.)

They are there for a good reason.