Repository: godot
Issue: Mono Android Export: **ERROR**: Cannot instance script because the class 'Main' could not be found. Script: 'res://Main.cs'.t   :    At: modules/mono/csharp_script.cpp:2942:can_instance() - Method failed. Returning: __null
Labels: platform:android,topic:porting,topic:dotnet

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**Godot version:**
<!-- Specify commit hash if using non-official build. -->
3.2.3.stable.mono.official


**OS/device including version:**
<!-- Specify GPU model, drivers, and the backend (GLES2, GLES3, Vulkan) if graphics-related. -->
Arch Linux, tried GLES2 and GLES3
Mono JIT compiler version 6.12.0 (makepkg/a22ed3f094e Tue Dec 22 06:01:50 PM -03 2020)
[android_export_bug.zip](https://github.com/godotengine/godot/files/5898607/android_export_bug.zip)


**Issue description:**
<!-- What happened, and what was expected. -->
Some scripts are not found, some are found. My project consists of 4 scripts where 2 are not found resulting in the issue that they are not found / loaded.
The game works without any issues on Desktop (tested on linux and windows export inside wine)

**Steps to reproduce:**
Add a class member of type `System.Drawing.PointF`. The issue is also reproducable with `System.Drawing.Point`
Export project for android and run it on the phone.

**Minimal reproduction project:**
<!-- A small Godot project which reproduces the issue. Drag and drop a zip archive to upload it. -->
[android_export_bug.zip](https://github.com/godotengine/godot/files/5898608/android_export_bug.zip)
Log:

```
01-30 17:18:25.984  1384  2126 I InputReader: Device reconfigured: id=4, name='NVTCapacitiveTouchScreen', size 1080x2340, orientation 1, mode 1, display id 0
01-30 17:18:26.012  2361  2651 D EglHelper: createEglContext start
01-30 17:18:26.013  2361  2651 D EglHelper: createEglContext done
01-30 17:18:26.013  2361  2651 D EglHelper: createEglSurface start
01-30 17:18:26.014  2361  2651 D EglHelper: createEglSurface done
01-30 17:18:26.047  8291 15620 W ngine.miningbo: Accessing hidden method Landroid/app/ActivityThread;->currentActivityThread()Landroid/app/ActivityThread; (greylist, JNI, allowed)
01-30 17:18:26.048  8291 15620 W ngine.miningbo: Accessing hidden method Landroid/app/ActivityThread;->getApplication()Landroid/app/Application; (greylist, JNI, allowed)
01-30 17:18:26.048  8291 15620 I godot   : Mono: Log file is: '/data/user/0/org.godotengine.miningbot/files/mono/mono_logs/2021_01_30 17.18.26 (8291).txt'
01-30 17:18:26.105  2361  2361 I OpaEnabledReceiver: Dispatching OPA eligble = false; AGSA = false; OPA enabled = false
01-30 17:18:26.105  2361  2361 I OpaLayout: Setting opa enabled to false
01-30 17:18:26.105  2361  2361 I OpaLayout: Setting opa enabled to false
01-30 17:18:26.296  8291 15620 E godot   : **ERROR**: Cannot instance script because the class 'Main' could not be found. Script: 'res://Main.cs'.
01-30 17:18:26.296  8291 15620 E godot   :    At: modules/mono/csharp_script.cpp:2942:can_instance() - Method failed. Returning: __null
01-30 17:18:26.309  8291 15620 E godot   : **ERROR**: Cannot instance script because the class 'Player' could not be found. Script: 'res://Player.cs'.
01-30 17:18:26.310  8291 15620 E godot   :    At: modules/mono/csharp_script.cpp:2942:can_instance() - Method failed. Returning: __null
01-30 17:18:26.326  8291 15620 I godot   : map[0, 0 = COPPER
```