Aptoide TV is some backdoor BS anyways, do yourself the solid & avoid it.
I'm having the same issue except i'm using android tv on my sony tv. I can't download anything with puffin
I think it might be a matter of authority.
The other thing you could attempt is download the apks onto a flash drive with a different device, plugging it into the mi box, accessing it with a file browser app and installing it through that
Try downloading it on your laptop and save the file in a pen drive. Connect it to TV and try installing. Worked in my case when I was trying to install an app.
Isn't this simply related to allowing installations from unknown sources in security settings ??
Try using puffin browser
It's the browser you're using. Find a browser that supports the downloading feature. I use Chrome on my Shield.
Daft question, have you checked the browser's permissions? Does it have the storage permission enabled?
Happening on my nvidia and mi box on puffin tv browser.
Is apkmirror safe ? When there is play store why you go for external website ? Or some apps not available on playstore ? Am i right ?
If you download the apk from the usual google store used for phones or other sites that supply APK not fit for use in TVs, you will tend to get this message. This is because the version codes used in phones and TV are not the same; probably they are different devices having different OS. For example, TV uses remotes whereas phones uses keyboard. TV for viewing whereas Phone for communicating etc. They also have different type of CPU. If you want to use apk for TV and set top box, make sure it is the apk designed for Android TV and not ordinary phones.
What device are you using?