确保考虑到以下建议:

Your build variants and Flavors should be same(App installed and new one), usually release Signature file must be the same(*.jks file) The version you set in build.gradle or AndroidManifest have greater value compared to current version(it is recommended to set version in build.gradle) URL is correct(doesn't have typo) and server is reachable(WebService/WebMethod/WIFI is running/available and ...) File downloaded completely File saved correctly into desired directory Setting for Data and Type in setDataAndType is correct

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.

如果应用程序已经安装到或移动到SD卡上，然后连接了USB线，导致SD卡卸载，也会出现“应用程序未安装”错误。

在这种情况下，关闭USB存储或将应用程序移回内部存储可以解决这个问题。

我也遇到了同样的问题，下面是解决方法:转到Manifest文件，确保你有“Debuggable”和“Test Only”属性设置为false。这对我很有用:)

如果您有该应用程序的以前版本，请先尝试删除它，现在我的问题已通过该方法解决。

我知道这是一个老帖子，但对新用户可能有用。我也遇到了同样的问题:我的应用程序在调试时工作得很好。当我签署APK时，我得到了同样的消息:“应用程序未安装”。

我修复了卸载JDK(我使用的是JDK -6u14-windows-x64)并安装了一个新的JDK (JDK -6u29-windows-x64)。导出并再次签署APK后，一切正常!

恢复，我的问题是在JAVA版本。谢谢的甲骨文! !