That looks like a message from your local machine's virus scanner/malware or something along those lines. You'd need to allow the traffic out from your application so you can authorize.
Дело в том, что программа Rclone позволяет использовать Яндекс.Диск в качестве инфраструктурного компонента, а Яндекс.Диск - это персональный сервис, который не рассчитан на решение таких задач. Поэтому мы не поддерживаем работу связки Rclone - Яндекс.Диск.
The thing is that the rclone program allows to use yandex.disk as infrastructural component, but yandex.disk is personal service that isn't designed to solve such cases. Therefore we do not support the work with rclone.
It's fairly easy to create your own token here. It's probably advisable to also set a custom user-agent. Note that applications are supposedly reviewed manually but appear to be approved instantly right now.
Yes I notice the same for myself on 2 servers past some weeks, Yandex has BLOCKED rClone's programattic access.
When you do rclone authorize "yandex"
it opens the Authorization page. As shown in the screenshot, if you hover over the button "I understand the risk", it will show you error message :
This client is blocked due to malicious actions and thus denied access
How to ask rclone authors and developers to add change id and change client ability?
I would like to continue using Yandex.Drive, I bought two years ago...
With such hostile position of Yandex team towards open-source software we'd rather need switches to mask Rclone (callback port and user agent). But I'm not sure if they are worth it. There are tons of alternative clouds.