custom_theme setting not apparently working with a .tres file?

[Sslaxx]

Operating system or device - Godot version:
Linux 64-bit (Ubuntu 16.04) 2.1 rc1 (latest pull as of time of typing).

Issue description (what happened, and what was expected):
Setting Scene->Project Settings->Display->custom_theme to Assets/UI/Themes/Default.tres causes Godot to abort execution when testing the scene. The scene being tested, and the debugger process, appear to crash.

ERROR: load: No loader found for resource: res://Assets/UI/Themes/Default.tres
At: core/io/resource_loader.cpp:218.
shit?: Connection reset by peer
ERROR: read: Server disconnected!

At: drivers/unix/stream_peer_tcp_posix.cpp:276.

Steps to reproduce:
Add a custom theme to a project via the Display tag of Project Settings.

Link to minimal example project (optional but very welcome):
custom_theme_issue.zip

[Sslaxx]

Whilst not strictly related, this build of 2.1 no longer saves to .res/.xres. It can save to .xml though. But the file option from custom_theme doesn't recognise .xml, only .res and .tres. Forcing it to load the .xml file anyway gives this:

ERROR: load: No loader found for resource: res://Assets/Fonts/Roboto-Regular-16-bitmap.fnt
At: core/io/resource_loader.cpp:218.
ERROR: poll: res://Assets/UI/Themes/Default.xml:3: <ext_resource> referenced nonexistent resource at: res://Assets/Fonts/Roboto-Regular-16-bitmap.fnt
At: core/io/resource_format_xml.cpp:1448.
ERROR: load: Condition ' err!=OK ' is true. returned: RES()
At: core/io/resource_loader.cpp:142.
ERROR: load: Failed loading resource: res://Assets/UI/Themes/Default.xml
At: core/io/resource_loader.cpp:218.
shit?: Connection reset by peer
ERROR: read: Server disconnected!

At: drivers/unix/stream_peer_tcp_posix.cpp:276.

https://dl.dropboxusercontent.com/u/67740160/Default.xml is the .xml theme file created.

[Barina]

Same issue with 2.2alpha
after setting a custom theme (.tres), app crash at run
and after restarting the editor (with the game saved with the custom theme) it won't launch the project, it just crashes again (just remove the custom theme from the cfg file to fix that)
any workaround?

[Sslaxx]

Still an issue as of 3.0 build 3873362.

[reduz]

I'm not sure if this is a bug, I think you have to save the resource by specifying paths as relative.
The problem is that a tutorial was never made for this

[Jellonator]

I'm having this same issue as well. Except in my case instead of crashing, it just continues with the default Godot theme (rather than loading the custom theme).
Using Ubuntu 17.04 x86_64 with Godot 3.0 beta 2.
Here's the full terminal output:

$ godot
No touch devices found
OpenGL ES 3.0 Renderer: Quadro 1000M/PCIe/SSE2
GLES3: max ubo light: 409
GLES3: max ubo reflections: 455, ubo size: 144
ERROR: _load: No loader found for resource: res://theme.tres
   At: core/io/resource_loader.cpp:185.
ERROR: register_scene_types: Error loading custom theme 'res://theme.tres'
   At: scene/register_scene_types.cpp:234.
ARVR: Registered interface: Native mobile

[akien-mga]

Can one of you provide an example project compatible with 3.0?

[akien-mga]

We have now entered release freeze for Godot 3.0 and want to focus only on release critical issues for that milestone. Therefore, we're moving this issue to the 3.1 milestone, though a fix may be made available for a 3.0.x maintenance release after it has been tested in the master branch during 3.1 development. If you consider that this issue is critical enough to warrant blocking the 3.0 release until fixed, please comment so that we can assess it more in-depth.

[reduz]

Well, given editor themeing was rewritten completely for 3.0, I would close this.