Godot: Godot 3.0 instantly crashes when creating a new C# script with Mono 4

[aaronfranke]

Godot version: 3.0 rc2 (with Mono)

OS/device including version: Linux - Xubuntu 16.04 LTS 64-bit, Mono JIT compiler version 4.2.1 (Debian 4.2.1.102+dfsg2-7ubuntu4) (the version from the Ubuntu repos via mono-complete)

Issue description: I tried to create a new C# script. Instead, it just crashes Godot instantly.

Steps to reproduce: On any object, Node -> Script -> New Script -> C# -> Create, instant crash.

Minimal reproduction project: TestingGodot.zip

STDOUT, STDERR, and godot/mono/mono_logs Logs: mono_logs.zip

[akien-mga]

Mono 4.2.1 is likely too old for Godot, which is built against Mono 5.4.1 (current stable) and likely requires at least a 5.x version for compatibility.

A workaround would be to install the latest Mono using the upstream PPA for Ubuntu (removing before the mono-complete metapackage and its deps): http://www.mono-project.com/download/

Regardless, we need to check the version of the Mono SDK Godot will try to use, and prevent using it if it's older than a version to be determined (5.0?). @neikeq

[aaronfranke]

A warning when trying to use an outdated Mono version would still be a good idea.

[exts]

@aaronfranke is this still the case with 3.1 beta & 3.0.6 stable?

[akien-mga]

Mono is now distributed with the Godot binaries, so it should no longer be a problem.