Spine launcher is unable to start version 3.8.99. Verified with another user on Discord that we got the same error.
Spine Launcher 4.1.14
Spine Editor 3.8.99 Professional
spine.log
Spine Launcher 4.1.14
Esoteric Software LLC (C) 2013-2022 | http://esotericsoftware.com
Windows 10 Home amd64 10.0
NVIDIA Corporation, NVIDIA GeForce GTX 1070/PCIe/SSE2, 4.6.0 NVIDIA 531.79
Launching: Spine 3.8.99 Professional
ERROR: Error running legacy Spine launcher:
java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at com.esotericsoftware.spine.editor.launcher.Launcher.main(_:734)
Caused by: java.awt.AWTError: Assistive Technology not found: com.sun.java.accessibility.AccessBridge
	at java.desktop/java.awt.Toolkit.newAWTError(Unknown Source)
	at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Unknown Source)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(Unknown Source)
	at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(Unknown Source)
	at java.base/java.util.stream.AbstractPipeline.copyInto(Unknown Source)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source)
	at java.base/java.util.stream.AbstractPipeline.evaluate(Unknown Source)
	at java.base/java.util.stream.ReferencePipeline.forEach(Unknown Source)
	at java.desktop/java.awt.Toolkit.loadAssistiveTechnologies(Unknown Source)
	at java.desktop/java.awt.Toolkit.getDefaultToolkit(Unknown Source)
	at s.Mmx.<clinit>(_:28)
	at com.esotericsoftware.spine.editor.launcher.Launcher._(_:769)
	... 5 more
Caused by: java.lang.ClassNotFoundException: com.sun.java.accessibility.AccessBridge
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source)
	at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
	at java.base/java.lang.Class.forName0(Native Method)
	at java.base/java.lang.Class.forName(Unknown Source)
	... 19 more
E r r o r   1 2 7 :   T h e   s p e c i f i e d   p r o c e d u r e   c o u l d   n o t   b e   f o u n d . 
 
 Exception in thread "main"