We have updated JsonRollback in Skeleton Viewer 4.0.54-beta to support specifying a version of 3.8 to go from 4.0.xx to 3.8.99.

So that means we can go back from 4.x to any 3.8.x maybe even 3.7.x?

p.s. Cant open beta jar, Java updated

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: com/badlogic/gdx/ApplicationAdapter has been compiled by a more recent version of the Java Runtime (class file version 57.0), this version of the Java Runtime only recognizes class file versions up to 52.0
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$100(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$100(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

Nate wrote

@[محذوف] Sorry about that, we've uploaded Skeleton Viewer 4.0.53-beta which fixes that problem.

Hello, Skeleton Viewer 3.8.99 lacks the JsonRollback functionality too.

Hello everyone! We are trying to downgrade from version 3.8 to an older one. Prints a lot of errors. Then we tried to view the animations separately using skeletonViewer 3.8.99 - the black screen blinked and nothing happened. Java is updated.
As a test, the old 3.6 file with skeletonViewer-3.6.53 works perfectly

Hello, what errors are you getting precisely? did you already try to downgrade the project following these instructions?
Open project in an older version

Resolved

Hi! I'm trying to downgrade a json from 3.8.99 to 3.7 and having issues. I'm an animator, so I'm struggling with these kind of things.

I exported the .json with Nonessential data checked (and everything else unchecked).

I downloaded the Skeleton Viewer 4.0.54-beta from this site: http://de.esotericsoftware.com/spine-skeleton-viewer and put it into a folder on my desktop named "json" together with the .json I need downgraded.

I downloaded and installed the most recent Java version (Version 8 Update 281 Build 1.8.0_281-b09). I also checked, there is only one installed and it's version 8.

Then I ran this command:

java -cp "C:\Users\kerst\Desktop\json\skeletonViewer-beta.jar" com.esotericsoftware.spine.JsonRollback "C:\Users\kerst\Desktop\json\MainChara.json" "3.7" "C:\Users\kerst\Desktop\json\MainChara-2.json"

But I'm getting the attached error. What does it mean?

EDIT: I found the issue! I had the wrong Java version. I downloaded regular old java from java.com, but the correct one is the Java Development Kit you can find here: https://www.oracle.com/de/java/technologies/javase-downloads.html . You need to install it, reboot and then it should work.

Noody! THANK YOU!!!! With the Java SE Development Kit 15.0.2 it works!

warmanw wrote

We have updated JsonRollback in Skeleton Viewer 4.0.54-beta to support specifying a version of 3.8 to go from 4.0.xx to 3.8.99.

So that means we can go back from 4.x to any 3.8.x maybe even 3.7.x?

Sorry I missed this. Yes, you can. However, as of 4.0.68-beta we've made it easier: you can choose an older version when exporting JSON.

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

This is equivalent to using the JsonRollback tool, but is easier. Going back to an older version may still lose data and may still require manual fix up, such as deleting attachments or constraints that do not exist in the older version. Exporting to an older version is still not a recommended workflow, it is provided only to help recover work after from the catastrophic situation where a newer Spine version was used unintentionally.

Thank you, Happy tears.

Hello, I have around 300+ spine exports, And the project i need to update is very old, spine 3.x. I Don't think i'll be able to find all the spine projects.
I need to update it to 3.8.
Is there a way to change all the json files (assuming only changing the json will make it work).

@bilalmirza The process is: run 3.8, convert JSON to a project (.spine), run 4.0, export JSON from the project.

You can write a script to do it. I recently posted more information and the commands here:
Spine-Unity 3.8 to 4.0 Upgrade Guide

Thanks! just what i needed.
Sorry I missed that post, my bad.

All files were converted via tool you mentioned. Everything works perfect except for 1 file. Any idea why it could be?

Great! I can't tell from the problem from the screenshot, sorry.

In 3.8 when a constraint is applied, it may revert the changes made to bones by a previously applied constraint. In 4.0 that has been improved, but means your skeleton may not look the same as in 3.8 if you were relying on the constraint revert behavior. If that is the case, it will look wrong in both the editor and at runtime. To fix it you just need to find the constraint that you don't want applied and set the mixes to 0.

Sorry, I wasn't able to work on this for a month, It seem like the problem is related to skins(maybe) and not constraints, Or maybe the export itself.
I've removed meshes, constraints and skins in the following image. The scarf is exported as the fan.

I'm afraid I can't make much sense of what is going on, as I'm not familiar with your project. Does it look right in the editor? Have you tried rebuilding the atlas? Does it look right in Skeleton Viewer?

It looks right in the editor, and the skeleton viewer. Atlas rebuild doesnt work. I guess the problem is in the runtime on cocos2d-x end.

You'll need cocos2d-x to use the 4.0 runtimes if you are exporting from the 4.0 editor. If you are using the 4.0 editor to create an atlas for the 3.8 runtimes, you'll need to check Legacy output.

im on coocs2d-x 4.0. Spine v4 export crash, 3.7 crashes, and only one that works is 3.8 but with weird skin results mentioned above.

The spine-cocos2dx runtimes crash, or the Spine editor crashes? You can not use an export from e.g. version 3.8 in a Spine Runtime of version e.g. 4.0. Please make sure the Spine Editor version you exported from and the Spine Runtimes version match. If that is the case, and the Spine Runtimes still crash, then please send us the exported files and we can see if there's a bug in the runtime.

This issue was fixed by removing cocos2d-x default sp runtime and using the spines runtime https://github.com/EsotericSoftware/spine-runtimes
Thanks Mario for helping me out!
Cheers