[UnityAppController applicationDidReceiveMemoryWarning:]: unrecognized selector sent to instance...

[JosephCarrington]

Describe the bug If the app receives a memory warning while running a Unity view, it crashes.

To Reproduce Steps to reproduce the behavior:

1. Follow setup instructions for AR implementation for iOS.
2. Do something that is memory intensive (Like loading a lot of giant images, or just opening the profiler and waiting a few seconds)

Expected behavior applicationDidReceiveMemoryWarning should have a handler of some kind that actually exists.

Screenshots

Unity (please complete the following information):

• OS: iOS
• Version 2022.3.4f1

Smartphone (please complete the following information):

• Device: iPhone 14
• OS: iOS 16
• Version 16.5.1

[OgiJr]

Were you able to find a solution to this error? It causes my app to crash every time it has to do something memory intensive.

[alexandrefresnais]

I am impacted too on my AR app

[CodeEagle]

add - (void) applicationDidReceiveMemoryWarning:(UIApplication *)application {} in file UnityAppController.mm to fix this

[timbotimbo]

I just noticed the following in the Unity changelogs

iOS: Bring back the applicationDidReceiveMemoryWarning: to UnityAppController. (UUM-55367)

This is noted in versions

• 2021.3.33
• 2022.3.15
• 2023.2.2

I can't find when they removed it, but it looks like they fixed it themself.

[Update] I also found

iOS: Fixed low memory usage event not triggered when using Unity as a library. (UUM-20838)

Fixed in 2021.3.28f1, 2022.3.2f1, 2023.1.0f1, 2023.2.0a17

So updating Unity seems your best bet.

[Ahmadre]

I just noticed the following in the Unity changelogs

iOS: Bring back the applicationDidReceiveMemoryWarning: to UnityAppController. (UUM-55367)

This is noted in versions

• 2021.3.33
• 2022.3.15
• 2023.2.2

I can't find when they removed it, but it looks like they fixed it themself.

Good to know that they brought it to both 2021 + 2022.

[timbotimbo]

For reference, this is the function that Unity adds in 2021.3.33, which matches what @CodeEagle mentioned earlier.

- (void)applicationDidReceiveMemoryWarning:(UIApplication*)application
{
    // We handle it by subscribing for notification, this one is only a placeholder for stuff like forwarding in UaaL setups
}