Nexus 7 2013 Marshmallow, won't allow to install app--apk file.

If you are looking for solution in forums, they will probably ask 'why you need install app without Google play store' or 'are you trying to install cracked app--illegally unlocked copyright version app'.

I tell you why I need this.
I bought secondhand Nexus 7 2013 (second generation) tablet for my sister so I don't want to do all the things like google log-in process and wasting my limited internet resources (I don't have unlimited internet access.) for downloading apps and sync the app data,
for just testing the tablet.

I just wanted to install some apps like movie play app, photo viewer app, music player app, camera app and some 3d-ish game app or copy some video file so I can check whether this secondhand tablet will work properly or not.

So I just need to install two to four apps to testing the tablet.


Here is the tablet's version info:
Nexus 7 and Android 6.0.1

Screenshot of Settings -> About tablet in Nexus 7

check 'Unknown Sources' in settings for install apk files

If you searched web for 'how to install app (apk file) in Nexus 7', you will find solution like this
Settings -> Security -> turn on 'Unknown sources'

Screenshot of Settings -> Security in Nexus 7

but this doesn't work. Because tablet still don't allow to installing the app.

Screenshot of Settings -> Storage -> Internal Storage

Screenshot of Settings -> Storage in Nexus 7

'Explore' to install the apk file.
But you will get message like this:
'Cannot open file'.

When you trying to install the apk file, you will get error message like this.

How to transfer apk file in Nexus 7.

Many of Android smartphone and tablet probably will have MicroSD memory card slot so most cases you can copy files easily. And not only that.
They will probably have USB-OTG function which you can simply put the usb memory card to the smartphone or tablet via USB-OTG cable.

But Nexus 7 don't have memory card slot. So what you can do is send file via bluetooth or NFC. Or use internet or connect PC with usb cable.

But it looked like apk file won't allow to do transfer via bluetooth or NFC. So you can do it via internet or connect PC with usb cable.


So I use send-anywhere websites to transfer apk file:

trying to send file via send-anywhere.com

and then use download app to install apk file but I've got same error 'Cannot open file'.

'Downloads' app to install apk file but same error - can't open file

I can transfer to the apk file but can't install it.




Only way to install the app is use android app development tool ADB.

I already install the Android Development Tool on my PC and this article became quite long so I will not explain how to get and use the tool.

You can follow one of these articles:

• The Easiest Way to Install Android's ADB and Fastboot Tools on Any OS
• How to Install and Use ADB, the Android Debug Bridge Utility
• [TOOL] [WINDOWS] ADB, Fastboot and Drivers - 15 seconds ADB Installer v1.4.3

You don't need install whole Android Development Tool to get ADB file. You can find only ADB file and Android USB Driver for Windows(or possibly your system already have it).


You need to turn on 'USB debugging' option in 'Developer Options'. That means it must turn on 'Developer Options' via clicking 7 times in Settings -> About tablet -> Build Number.
* detail guide is here How to enable developer settings on Android 4.2 | Android Central


Connect tablet to PC and then Window+R to type 'cmd' to enter 'Command Prompt' console mode.

install apk file in Nexus 7 via ADB tools - Windows

Make things easier, copy the apk file in the same directory as ADB file is in, and change apk filename short like this because Windows Command Prompt won't easy to handle long filename.
For example here is 'adb install es.apk'.

Finally, install the apk file via ADB from PC.

So install the File Explorer app like ES File Explorer should be better choice. Because this app will allow to install apk file like this:

install app from ES File Explorer in Nexus 7

install app from ES File Explorer in Nexus 7

installed app from ES File Explorer in Nexus 7

If you need more detail guide about use ADB, you can do similar like this: [GUIDE] How to install APK Files on your Nexus Player | xda-developers forum
This guide is for Nexus Player but most of Android smartphone and tablets were all the same.




P.S. I'm quite confusing because I did this(install apk files) many times with variety of Android smartphone and tablet. Most of times, I just sent apk file via bluetooth and installed easily with turn on 'Unknown sources'.
So this is probably Marshmallow problem. Or Google probably blocked 'Unknown sources' option.