@Andy15 if all the apps on your Roku device do not work, then it might be an issue with your router/modem. If it’s not a router/modem issue, you may need to check if the Roku is powered through your TV’s USB port or the wall outlet. If it’s powered through the wall outlet, you probably need to do these steps, and in the correct order as always:
1. Remove each channel affected with the device.
2. Settings > System > Power (If not applicable skip to the next step!) > System Restart.
3. Reinstall each channel affected with the device.
If none of those steps work, even when in the correct order, then all I can suppose is that you probably own a defective Roku device unit. If your Roku is a model that’s out of warranty now, it’s probably time to upgrade to a newer Roku model. Or, if it’s still under warranty, you could contact Roku customer support (https://support.roku.com/contactus) about your Roku, and/or return the unit to the store for a replacement unit.
I’m into videotapes and old electronics stuff, including extenders, converters and analog 4:3 TV sets (which are obsolete these days), and Miss Bianca is my favorite character in Disney’s The Rescuers (1977) and its sequel, The Rescuers Down Under (1990). I am not a Roku employee, only a user like you. ~ Jordan
Roku Express+ 3910X