Property not found: _global_script_class_icons emitted in 3.1 project

[Title-Pending]

3.1:

OS/device including version:

PC
Window 10
NVidia 1080 TI 11GB

Issue description:

WARNING: _get: Property not found: _global_script_class_icons
At: core/project_settings.cpp:195

Steps to reproduce:
Download Kids Can Code File
https://github.com/kidscancode/topdown_tanks/releases/tag/part11
Open the file in Godot 3.1
Then
"WARNING: _get: Property not found: _global_script_class_icons
At: core/project_settings.cpp:195"
should appear.

Note: After file is exported in godot 3.1,
"WARNING: _get: Property not found: _global_script_class_icons
At: core/project_settings.cpp:195"
Will not appear again...

Minimal reproduction project:

https://github.com/kidscancode/topdown_tanks/releases/tag/part11 is the original file before conversion.

[willnationsdev]

This should ideally be something that doesn't result in a warning like that. You say that the error stops after the "file is exported" though? That's probably because the engine is creating that dictionary at some point. It's just also attempting to read the data before it has been created. Will have to look into that.

So, it's reporting the warning when it tries to read the data and it isn't there, but later on it's creating the data which stops subsequent warnings from popping up. Just need to make sure the data is made before it's ever accessed at any point.