For troubleshooting purposes you may need to know your Roku model and model number. You can find these via Roku menu path Settings > System > About.
There are some router setting issues that can prevent establishing Roku wifi connections. And to make matters worse, some of them can be caused by recently-reported router updates. These updates have primarily been reported with routers supplied by internet providers (Comcast/xfinity, Cox, and AT&T so far), but it's possible they could also occur with other internet providers or user-owned routers that have received similar updates.
ROKU CANNOT FIND LOCAL WIFI NETWORK AT ALL A) Some Roku models, notably Roku Express/Express+ (not the relatively new Express 4K/4K+ models 3940/3941) and Premiere/Premiere+ (model numbers above 4620), are lower end units with single band Wi-Fi radios that only support the 2.4 GHz band. They, and many other devices of all sorts that are 2.4 GHz only, can't even see the 5 GHz band, let alone connect to it. Some recent router updates have turned off the router's use of the 2.4 GHz band. If you have a 2.4 GHz only Roku model and a dual band router with both 2.4 and 5 GHz bands, be sure the router's 2.4 GHz band is turned on.
B) In the 2.4 GHz WiFi band, all Rokus support channels 1-11, as are used in North America. If your router supports 2.4 GHz channels outside this range make sure your router is set to use a channel in this range and that you aren't using an auto setting that could select channels outside this range.
C) Rokus with dual-band wifi radios can connect to the 5 GHz wifi band in two ranges of channel numbers, 36-48, and 149-165. If your router supports 5 GHz channels outside these two ranges make sure your router is set to use a channel with these ranges and that you aren't using an auto setting that could select channels outside these ranges.
If you need to make configuration changes on router equipment supplied by your internet provider but you have no access to its settings, you may need to request your internet provider to make the changes for you.
If your problem was not caused by any of the above, often a restart of the router (even if other devices are still connecting) followed by a restart of the Roku will allow the connection to be reestablished. Depending on your Roku model and Roku version number you'll find the "System restart" option under either "Settings > System > Power" or "Settings > System", or if more convenient you can just remove the Roku's power for a few seconds and let it restart.
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
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