Update app for new Android version and remove warning of old Android version

[nicoali]

i built the apk and all is fine and working!

app works fine also on smartphone with newest android version but when people install it appears a warning "This app has been created with and old version of android and could not work properly.... upgrade or contact developer"

i tryed to edit the file gradle:

android {
//compileSdkVersion 25
//buildToolsVersion "25.0.0"
compileSdkVersion 30
buildToolsVersion = "30.0.3"
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}

defaultConfig {
minSdkVersion 14
targetSdkVersion 30
}
warning disappeared but after splash screen app crashes

while if i compile with old version of sdk works fine except for the warning!

What can i do to remove that warning?