Are you experiencing issues like freezing when streaming on your Roku 4?  You could either soft reset it via Settings menu or you can hard reset it via button.

Roku 4 fix issues factory reset streaming

Like any other Roku in the past, the rest goes the same way:

Short press of any Roku reset button will reboot Roku.
Long press of any Roku reset button will factory reset Roku

You can find the reset button on the bottom of the Roku.

Some people are reporting issues with not being able to add channels where it just spins and spins.  If this is happening to you and factory reset doesn’t fix the issue, contact Roku customer support.  1 (888) 600-7658

From the sheer amounts of complaints I read of issues relating to the Roku 4, I am surprised that Roku hasn’t done a recall yet.  People are reporting issues with Roku 4 not working with Sharp TV’s in ultra high definition mode.  If it doesn’t work well with Sharp TV–I bet you it won’t work well with some other TV’s brands.