I had a similar issue: Black screen launching HBO Max channel after signing up for the 1 month free trial through Roku.
My solution:
I tried all of the channel install/remove, device restart, add subscription, cancel subscription nonsense posted on this forum. Clearly wasn't my issue. It appears to be a bad credential hand-off from Roku to HBO Max when signing up for the free trial. Once I verified my HBO Max account was active on their website, things worked well.
Same problem and it’s a new subscription. Just wanted to watch peacemaker. I turned off/on the Roku smarttv and I restarted it after deleting and reinstalling the app. I restarted the TV before reinstalling the app too. HBO and Roku are just pointing fingers. I checked for updated and app says it’s updated.
Using a TCL Roku TV.
I got my HBOMAX app to work by downloading the app on my phone. I logged out of all devices. I changed my password using forgot password. I verified my email. I checked settings in the hbomax app. I looked at manage devices and subscriptions and everything was updated.
this did not work for me
I used the mobile app and I signed in online on my computer browser to hbomax.com. Before I changed my password and verified my account email the subscription wasn’t updated.
Worked for me.
The reason you need to sign out of all the devices is that Roku might be holding onto your old HBO login information. As a result, the new HBO Max channel will crash.
Alternatively, you can also unsubscribe from HBO. Then remove the HBO channel and restart your Roku device. Re-add the HBO Max channel after you did all that.
I followed your directions.
Yet the HBO Max channel continues to not work (Logo on purple screen briefly, replaced with black screen with three rotating dots at bottom. Screen disappears in about 30 seconds and I am kicked back to a Roku screen.)
I had similar problems. I watch HBO Max through my Roku. Apparently, I'd used a different email address for each of them. Changed my email address to match both and that seems to have cleared up my problem.
I restarted my Roku TV by going to Settings / System/Power/restart
HBO Max, which was not loading previously, loaded successfully