Spectrum says unable to complete request
Are you using a Roku model supported by Spectrum? (Check model and model number via Settings > System > About)
Source: https://support.xfinityoncampus.com/hc/en-us/articles/115004909567-For-Roku
The "XFINITY Stream Beta" channel works on these Roku devices:
Roku TV (5XXX, 6XXX: Models within the 5000 and 6000 range)
Streaming Stick (3800, 3600)
Streaming Stick+ (3810)
Express (3900, 3700)
Express+ (3910, 3710)
Premiere (4620)
Premiere+ (4630)
Ultra (4660, 4640)
Roku 4 (4400)
Roku 3 (4200, 4230)
Roku 2 (4210)