umbekannt Ignore the error for now, everything works both in the editor and in the build. Create SkeletonData Resource, then assign .skel or .spine-json and atlas to it. Add a SpineSprite node to scene and assign the newly created resource to it. The skeleton will show up and work as intended.

Hopefully, this can be resolved soon.

Related Discussions
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Godot 4.1 doesn't recognize any skeleton format, neither .spine-json nor .skel

    umbekannt You have .json instead of .spine-json. http://esotericsoftware.com/spine-godot#Exporting-for-Godot

    Note: You should prefer binary skeleton exports over JSON exports, as they are smaller in size and faster to load. If you must use JSON, make sure the file extension is .spine-json instead of .json. If you have an existing project that still uses .json export files, you can use this Python script to convert it to the new .spine-json extension.

    Image removed due to the lack of support for HTTPS. | Show Anyway

    And try one format at a time, delete contents in Godot, then reexport with correct file extension.

    I have the same problem with the .spine-json format 🙁

      umbekannt uff, then I dunno. Try resetting Spine export Pack Settings to Default. There's a button for it, then disable the Premultiply alpha checkbox. There's a note in docs that premultiply alpha is not supported. That's my last guess.

      It still doesn't work, but thank you very much for your time; you're a great person!

        8 days later

        umbekannt Hey, if you're still around, can you share your OS and hardware specs in the very unlikely case that they are a contributing factor?

        Here're mine:
        Spine 4.1.23
        OS: Windows 11 Home version 22H2
        CPU: slightly downvolted i9-12900k
        RAM: 32Gb DDR4
        Drive/s where Godot/Spine reside: Samsung 980 PRO PCle 4.0 NVMe M.2
        GPU: RTX 3070Ti /w latest Nvidia gaming drivers

        10 days later

        I am using Godot 4.1.2 with C# support
        When exporting as binary I still cannot seem to use the .skel file in Godot editor.

          Lick I tried to reproduce the problem but unfortunately was not able to see the error. Are you encountering this problem on Windows or Mac?

          • Lick replied to this.

            Misaki
            Hello Thanks for the response!
            I am on Windows 10. I think it may have to do with my Spine version...
            What is the minimum Spine version that is compatible with the Godot runtime?

              Lick spine-godot works with data exported from Spine 4.1.xx, so it cannot be imported if your data was exported with a version prior to 4.1. For your information, the data I tried was exported from Spine 4.1.23 (and I did not get the error).

                I've been having a similar problem and was trying to diagnosis it using this thread: https://esotericsoftware.com/forum/d/24751-spine-godot-c-support/19 only to realize it wasn't addressing this problem but just that stuff wouldn't work after importing in general, here the example projects seem to run fine despite this error so maybe it's ignorable for now? Running windows 10 with spine version 4.1.23, with premultiply alpha disabled on exporting, tried running godot on different drives too.

                10 days later

                The weird directory path is probably from the build machine.

                I do want to use Godot, but I'm reluctant while this issue persists. If importing already is so error prone, I shudder to think what might happen 6-12 months in production.

                a month later

                Unfortunately, this still happens in Godot Engine v4.2.stable.custom_build.46dc27791

                Whatever this is, it must be on the runtimes implementation side. I tried renaming everything to snake_case in case this is an issue with Godot's naming convention since I've heard it can mix up capital and lowercase letters on Windows. Also tried different SSDs in case of weird permissions thing. Still no dice.

                This is merely an error message, and as you found, both editor and exports work fine despite it.

                I have spent 2 days figuring out where it is coming from to no avail. We aren't doing anything crazy in the atlas importer either.

                So for now, you can simply ignore this error and carry on. If I find a solution, I'll update the issue and this thread.

                  Mario Also had a crash on asset reimport over existing assets in the project, but I can't repro reliably and can't tell if it's related.

                  6 days later

                  Mario I'm currently experiencing the same issue, yet it's not ignorable - following the tutorial I'm not able to import either the .skel-json file, nor the .skel file for either method. The file icon is X'd out and I just get "Error importing 'res://Art/Output/skeleton.skel'." messages. I can't just proceed as it gives me errors if I try use the file. If I drag the skel file to the Skeleton file res, it says:
                  "No loader found for resource: res://Art/Output/skeleton.skel (expected type: )"
                  If I try load it through the path it says:
                  "Cannot load resource from path 'res://Art/Output/skeleton.skel'"
                  As a result, the skeleton file res just stays <empty> as godot just wont let me input the file at all to it. currently, there's no way to continue past this if the error occurs, as far as I can see.

                    UnNorm I think @umbekannt also could not import skeletons at all, so it doesn't seem to be just cosmetic for everyone.