deleted channel after followed can not be unfollowed

[starinspace]

Describe the bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior: Imported some channels through the file exported from YouTube. All channels worked. But one of the channel has deleted their channel. It does show an icon without text. When pressing on it it just give an error and it's not possible to unfollow or delete it from the follow-list.

Expected behavior Maybe see that the channel don't work and ask for delete the link in list?

Screenshots

Setup:

• Android version: 10
• Is Your device rooted? No
• Do You use Tor or any VPN service with your device? No
• App source [e.g. FDroid, Downloaded from GitHub, self build] from github
• App Version v2.978
• App Flavour Extra

[starinspace]

Or how can I delete that channel from the follow list?

[jcsalomon]

Unsurprisingly, the same issue applies to channels removed by YouTube for rules violation.

Expected Behavior Some method of removing a channel from the subscription list that does not depend on the current subscription being valid.

[un-logic]

Ideally, a new tab for managing subscriptions to channels is needed, where one could remove subscription and grourp or prioritise channels.