Please note that this bug wasn't present on JBoss 7.1 / same WAR artifact

This is full staktrace from our applicaion.

11:13:32,130 SEVERE ch.mitsa.credoc.ui.views.messages.MessagesTable (default task-9) Error getting message payload: : javax.xml.transform.TransformerConfigurationException: Translet class loaded, but unable to create translet instance.
at com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl.defineTransletClasses(TemplatesImpl.java:369) rt.jar:1.7.0_71
at com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl.getTransletInstance(TemplatesImpl.java:383) rt.jar:1.7.0_71
at com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl.newTransformer(TemplatesImpl.java:418) rt.jar:1.7.0_71
at com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl.newTransformer(TransformerFactoryImpl.java:765) rt.jar:1.7.0_71
at _redirected.TransformerFactory.newTransformer(_TransformerFactory.java:132) jboss-modules.jar:1.3.3.Final
at ch.mitsa.credoc.format.swift.impl.SwiftFormatter.getPrettyPrintedPayload(SwiftFormatter.java:196)
at ch.mitsa.credoc.engine.service.OutputService.getPrettyPrintedMessage(OutputService.java:54)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) rt.jar:1.7.0_71
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) rt.jar:1.7.0_71
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) rt.jar:1.7.0_71
at java.lang.reflect.Method.invoke(Method.java:606) rt.jar:1.7.0_71
at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:52)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.invocation.WeavedInterceptor.processInvocation(WeavedInterceptor.java:53)
at org.jboss.as.ee.component.interceptors.UserInterceptorFactory$1.processInvocation(UserInterceptorFactory.java:63)
at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:309)
at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:407)
at org.jboss.as.weld.ejb.Jsr299BindingsInterceptor.doMethodInterception(Jsr299BindingsInterceptor.java:82) wildfly-weld-8.2.0.Final.jar:8.2.0.Final
(...)