Continuous error when using Linutil

[Bertminator]

Describe the bug

Whenever I try to run many options in your linutil, I keep getting this same error:

E: The repository 'https://repo.vivaldi.com/stable/deb stable Release' is not signed

I'm not sure if this is a bug....I don't think so, but I am not sure what to do to fix this error. I get it anytime I try to build prerequisits, or do a full system update, or many other features you have in the linutil. If it's not an error, Please let me know what I can to do rectify this, as I love the script you are creating, but find I cannot use many of it's features. It worked perfectly fine the 1st time I ran it. What am I missing?

I'm not a programmer, so forgive my lack of knowledge....I'm also new to Linux Mint, so please keep answer simple for me.

Thanks.

[adamperkowski]

That's not an issue with linutil. It's an issue with apt. There is nothing we can do about it.

[adamperkowski]

I mean, we could --allow-unauthenticated but that doesn't solve the issue.