Emissor Gratuito CT-E

Bom dia,

Senhores,

Estou tendo problemas para assinar um CT-e esta dando o seguinte erro:

Alguém teve o mesmo problema e achou uma solução?

Ocorreu um erro inesperado!

detalhes:
Ocorreu um problema durante a assinatura
br.gov.sp.fazenda.dsge.certif.exception.DSGECertificadoException: Ocorreu um problema durante a assinatura
at br.gov.sp.fazenda.dsge.certif.Certificado.assinarXML(Certificado.java:696)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness.assinar(ConhecimentoTransporteBusiness.java:148)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness$$EnhancerByCGLIB$$e87b560c.CGLIB$assinar$1(<generated>)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness$$EnhancerByCGLIB$$e87b560c$$FastClassByCGLIB$$b6fbcfac.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:167)
at br.gov.sp.fazenda.dsge.model.dao.util.DSGEDAOInterceptorHelper.intercept(DSGEDAOInterceptorHelper.java:55)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness$$EnhancerByCGLIB$$e87b560c.assinar(<generated>)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness.assinar(ConhecimentoTransporteBusiness.java:186)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness$$EnhancerByCGLIB$$e87b560c.CGLIB$assinar$0(<generated>)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness$$EnhancerByCGLIB$$e87b560c$$FastClassByCGLIB$$b6fbcfac.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:167)
at br.gov.sp.fazenda.dsge.model.dao.util.DSGEDAOInterceptorHelper.intercept(DSGEDAOInterceptorHelper.java:66)
at br.gov.sp.fazenda.dsec.model.business.ConhecimentoTransporteBusiness$$EnhancerByCGLIB$$e87b560c.assinar(<generated>)
at br.gov.sp.fazenda.dsec.model.facade.ConhecimentoTransporteFacade.assinar(ConhecimentoTransporteFacade.java:138)
at br.gov.sp.fazenda.dsec.controller.PesquisarCteController.e(PesquisarCteController.java:562)
at br.gov.sp.fazenda.dsec.controller.PesquisarCteController.actionPerformed(PesquisarCteController.java:695)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$300(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)