ARGHHHHH !我试图安装为Unsigned Release APK时，正确的设置是DEBUG SDK。

一个小时过去了。

这个答案只与使用本机库(Android NDK)的应用程序相关。

在我的案例中，问题在于jniLibs中缺少一些用于目标电话CPU架构的本机库。因此，应用程序可以在模拟器上运行，但在真正的手机上，我看到“应用程序未安装”。

我最初只复制了x86架构的编译本机库，所以应用程序可以在模拟器上运行。但是，其他体系结构缺失(x86_64、armeabi_v7a、arm64-v8a)。在添加了缺失的*之后。所以所有架构的文件到jniLibs，“App未安装”错误消失了。

当我遇到这个问题时，我的自定义构建工具将ADT与用于iOS的证书一起使用(这当然不是我的第一个猜测，因为除了只有你应该有一个之外，Android证书似乎没有什么特别之处，他们只是RSA-1024证书，甚至自签名也是可以的，至少对于非市场安装)。

在marsmallallow中，在所有者和客户用户中都有。如果客人安装了相同的应用程序，我们不能在所有者安装相同的应用程序。我修复了这个删除客户应用程序

Clearly there are many causes of this problem. For me the situation was this: I had deployed to my nexus 7 (actual device) from within the Android Studio (v1.3.2). All worked fine. I then created a signed apk and uploaded to my Google Drive. After disconnecting my nexus from the usb, I went to the settings/apps and uninstalled my app (App1). I then opened google drive and clicked on my App1.apk and chose to install it (need to ensure you have allowed installation of apks in settings). Then I got the dreaded message "App not Installed"

Solution for me: go back into settings/apps and scroll though all apps and at the bottom was a pale version of my App1 (note the original App1 was at the top in Alphabetical order which was deleted as above). When clicking on the pale version it said "Not installed for this user". (I had set up my nexus to have more than one user). But in the top right corner there is a three dot button. I pressed this and it said "Uninstall for all users". Which I did and it fixed the problem. I was now able to click on App1.apk and it installed fine without the error.

对我来说，原因是我在同一部手机上使用不同的构建变体进行了多个构建:

所发生的事情是，其中一些构建是由我构建的，另一个是由另一个开发人员发给我的。试图安装开发人员，而我有其他构建(由我构建)导致上述错误。

所以修复很简单:删除我手机上的所有构建(不管构建变体)..然后安装我的同事发来的apk ..而且效果很好