No, it's not a known bad build. There has been a few reports of users getting a bad update. But I've been running 4155 for well over a week as a beta tester, but since it's now gone public I can say that. I have no issues with this build. I tried Disney+, Prime Video and YouTube with no issues.
There is a hidden menu that can sometimes roll your version back one time, but it has to be accessed from the Roku main screen. If it won't boot, you can't get to it.
Do you have an SD card inserted in the slot? If so, eject it and try again. Chances are it will now boot.
I hate making such a drastic suggestion, but if there isn't an SD card involved, you may need to do a hard reset and see if it will boot as if a new player. The Roku 4 is only 5 years old, so it shouldn't be on its last legs yet. My granddaughter is still using my old 4. Of course, if you have a 4K TV you might consider it time to upgrade to a player with HDR. That would be the Ultra, Premiere or the Stick+. The 4 does not support HDR, and honestly HDR is a bigger deal than 4K if your screen is smaller than 65".
Dan
Roku Community Streaming Expert
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