I'm trying to install apk file in Samsung but it says "You may not have proper app for viewing this content". I've checked "allow installation from unknown source" option in security, but no luck. Please help me to sort this out.
Such Issues generally occur when you try to open the file from within an Application (Messenger, Whatsapp etc.) other than File Manager (any such application with similar privileges) or Play Store.
So, please make sure you are accessing it from File Manager.
If you are not aware of the source of the APK and if it's not from a trusted source please don't install it directly.
This is not a problem only in Samsung, but in all mobiles including latest Xiomi not supporting installation from messangers like WhatsApp.
If you want to install apps you can open your file explorer and go to WhatsApp folder -> media folder and then WhatsApp documents. There you can find the apk file or you can search your apk file name or just search .apk and you can find the apk file.
For Xiaomi uses : Open file manager, you can find the latest files in the first page, or in the second page you can find an option 'apks'. In that you can find your apk file from WhatsApp.
I got same error because I was trying to install it from whatsApp and also I forgot to uninstall previous version of same .apk file from Mobile.First check if you have any previous version of apk. If you have it then uninstall it.Then go to File Manager->Internal Storage->WhatsApp->Media->WhatsAppDoc. Here you will find your apk file.Install it from there.Also turn on the option Allow installation from unknown sources from Setting->Security.
I think that might be because you don't have a .apk installer app on your device.
If you do have one then try opening that and installing the app from there. If it does not works that means that the APP is broken, requires a newer version of Android than the one you have on your device or it was designed to be used on a different type of device than what you have.
If you don't have an APK installer you will need to install one from the Google Play Store. Alternatively you can also use adb (Android Debug Bridge) to install apps, but that requires a computer.