iOS Flutter with Firebase : white screen and SIGABRT in FlutterAppDelegate on launch

Question

In more than one project now, and very inconsistently, I get a white screen upon launching my app, and Xcode showing an error, Thread 1: signal SIGABRT , on the line @objc class AppDelegate: FlutterAppDelegate .

These are iOS Flutter projects that make use of Firebase .

I'm looking for some solid universal fixes for this, because it appears to happen intermittently and takes a long time for me to resolve, which is usually after trying so many things that I dont' know what fixed it.

I'm going to be systematic about when it happens now, and when it doesn't, so I can make this question clear and useful.
My Xcode is currently version 11.0.0.
I have a Deployment Target of iOS 8.0.

• The crash happens when I run the app from the VS code debugger or from Xcode onto an iPad running iOS 9.3.5
• It doesn't crash when I run it from Xcode to an iPhone 6 simulator, or to an iPhone Xs simulator

Answer 1

OK - so - while putting the question together I (1) tried the app on the iPad device and it crashed, (2) tried the app on some simulators and it worked, then (3) retried the app on my iPad and it worked.

So a solution that works to fix this issue sometimes is to, from within Xcode:

Run the app on a simulator, then re-run it on your device