IssueTracker

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            ComposeDialogNavigationTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colors.background
                ) {
                    MainScreen()
                }
            }
        }
    }
}

@Composable
fun MainScreen() {
    val navController = rememberNavController()

    Scaffold(modifier = Modifier.fillMaxSize()) {
        NavHost(navController, "greeting") {
            composable(route = "greeting") {
                GreetingScreen(navController)
            }

            dialog(route = "dialog") {
                DialogScreen()
            }
        }
    }
}

@Composable
fun DialogScreen() {
    val navController = rememberNavController()

    Surface(modifier = Modifier.fillMaxSize()
    ) {
        NavHost(navController, "profile") {

            composable(route = "profile") {
                ProfileScreen()
            }

            composable(route = "about") {
                AboutScreen()
            }

            composable(route = "troubleshooting") {
                TroubleshootingScreen()
            }

        }
    }

}

@Composable
fun GreetingScreen(navController: NavHostController) {
    Scaffold(topBar = {
        TopAppBar(title = {
            Text(text = "Dialog Sample")
        },
            actions = {
                Row {
                    IconButton(onClick = { navController.navigate("dialog") }) {
                        Icon(Icons.Rounded.Person, contentDescription = "Profile")
                    }
                }
            })
    }) {
        Text(text = "Compose App - Tap the profile button")
    }
}

@Composable
fun ProfileScreen() {
    Box(modifier = Modifier.fillMaxSize()) {
        Text(modifier = Modifier.align(Alignment.Center),
            text = "Dialog - Press hardware back button")
    }
}

@Composable
fun AboutScreen() {
    Text(text = "About")
}

@Composable
fun TroubleshootingScreen() {
    Text(text = "Troubleshooting")
}

@Preview(showBackground = true)
@Composable
fun DefaultPreview() {
    ComposeDialogNavigationTheme {
        MainScreen()
    }
}

buildscript {
    ext {
        compose_version = '1.1.1'
    }

dependencies {

    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.1'
    implementation 'com.google.android.material:material:1.5.0'
    implementation "androidx.compose.ui:ui:$compose_version"
    implementation "androidx.compose.material:material:$compose_version"
    implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.4.1'
    implementation 'androidx.activity:activity-compose:1.4.0'
    implementation 'androidx.navigation:navigation-compose:2.4.1'

So trying this in the latest Navigation snapshot build, this no longer crashes, so upgrading to Navigation 2.5.0-alpha04 would be enough to "prevent" this crash.

However, that prevention seems to be more that Navigation does not recompose as often, thus avoiding this race condition where the dialog destination is destroyed (which is why the NavBackStackEntry is DESTROYED), but the actual Dialog composable is still on the screen.

This looks like a missed edge case when the fix for popping a dialog destination with navController.popBackStack() was fixed in b/206465487 - we also need to delay destroying the destination until the Dialog composable is disposed when dismissing the dialog.

This has been fixed internally and will be available in the Navigation 2.5.0-beta01 and 2.4.3 releases.