Why do phones with older Android versions fail to open certain apps?

[Eskee Segdoh]

Question, I developed an app for Android devices. It's called Crash. The app is similar to a messaging app. The problem is, I noticed that older versions of Android have a hard time or an error when trying to install the app. It has no issues installing on phones operating with Android 7.0 but earlier versions are a problem. I'm just trying to get to the bottom of it.

 

[Deleted User]

Hi, welcome to Android Forums.
I moved your thread to the Android Development forum, which is the place to ask application development questions.
It could be that you've set the minimum SDK configuration parameter to a high value, which precludes installation of the app on devices which have a lower version.
The minSdkVersion parameter is found in your AndroidManifest.xml file.

https://developer.android.com/training/basics/supporting-devices/platforms.html

And the SDK (aka API) version to Android version mapping can be found here

https://en.wikipedia.org/wiki/Android_version_history