Our engineers have discovered a small bug in the latest MHz Choice Roku app (4.4.3) which is causing this issue. Try the following steps as a workaround to get access to the content:
1) Press HOME on your Roku remote
2) Launch the MHz Choice Roku channel
3) Select any series
4) Select "Subscribe to Watch"
5) Select SIGN IN
6) The next screen should present your 4-digit activation code
7) Go to a computer or mobile device, open a web browser window and go to https://watch.mhzchoice.com/activate
8) Enter the 4-digit activation code in the box provided and click CONNECT DEVICE
9) The MHz Choice Roku app should now be activated and you can now watch programming.