This just started with my Roku TCL today. Multiple channels are doing this. Vudu, Amazon Prime Video, Netflix and others. All problem solving attempts didn't work.
Probably best to list what workarounds/solutions you attempted ("all" may be very different to you and others).
Did you try the list?
Known solutions/workarounds for apps not loading:
1) Check for updates: Settings/System/System updates/Check now - try again
2) Change your Theme to the Roku Default: Settings/Theme/Restore default theme - try again
3) Change your Screensaver to a Roku clock: Settings/Theme/Screensavers - try again
4) Remove SD card (if installed) - try again
5) Network connection reset: Settings/System/Advanced system settings/Network connection reset - try again
6) Completely unplug power from Roku for 10-15 minutes - try again
7) Factory reset: Settings/System/Advanced system settings/Factory reset <--- last resort