I have devices running a APK-file that i have provided. (Non-market) I now want to update the APK on those devices. To do this i send a email to the devices with an adress to the APK-file.
My problem is that when the users click the link, download the file, and start the installation process they get a error, "Application could not be installed" because the APK is already installed on the device.
BUT not all users get this error. It works for some and not for others.
And yes, the version is updated in the manifest.
Any suggestions to a fix, or a reason why this doesnt always work?
For you to be able to update your application old version to a new version you need to sign both versions with the same key. This explains how to do that in a detailed manner.
P.S. I read somewhere that it is worth uploading your application to Android Market even if you are not going to distribute it that way (just make it private). This way noone will be able to hijack your application.