有时是因为你的手机没有足够的空间。如果是这样，请尝试清理内存，为新安装创造空间。

我遇到了类似的问题，这是因为我试图在使用相同apk的先前版本的手机上安装apk，而两个apk没有使用相同的证书进行签名。我的意思是，当我使用相同的证书时，我能够覆盖以前的安装，但当我在不同版本之间更改证书时，安装就不可能了。您是否使用相同的证书?

检查Android版本。

如果你安装的是非市场应用程序，和不兼容的版本，你会得到这个错误。

应用程序的目标是2.3.4 您的设备是2.2 然后你会得到这个错误。

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.

我也遇到了同样的问题，即App显示为正在安装，但当点击图标时不会启动。经过一些头部撞击，我发现我已经愚蠢地放置了' android:exported="false" '为我的主启动器活动在AndroidManifest文件....一旦我删除它，应用程序启动正常。

使用Android Studio，我之前安装了APK的未签名调试版本(Build > Build APK)，在安装有签名的发布版本之前必须卸载它(Build Variant > Build Variant: release, Build > Generate signed APK)。