Run has failed while deploying the process - NullPointerException - at org.bonitasoft.engine.expression.impl.ExpressionImpl.copy

Hi

I'm using Bonita and design some processes.

Today I changed a process and add instantiation form and all contract inputs that I need. But after that, the process didn't run and these errors is show:

Run has failed while deploying the process  
org.bonitasoft.engine.expression.impl.ExpressionImpl.copy(ExpressionImpl.java:151)
org.bonitasoft.engine.expression.impl.ExpressionImpl.copy(ExpressionImpl.java:151)
org.bonitasoft.engine.expression.ExpressionBuilder.getNonNullCopy(ExpressionBuilder.java:575)
org.bonitasoft.engine.bpm.connector.impl.ConnectorDefinitionImpl.addInput(ConnectorDefinitionImpl.java:103)
org.bonitasoft.engine.bpm.process.impl.ConnectorDefinitionBuilder.addInput(ConnectorDefinitionBuilder.java:63)
org.bonitasoft.studio.engine.export.builder.AbstractProcessBuilder.handleConnectorInputs(AbstractProcessBuilder.java:128)
org.bonitasoft.studio.engine.export.builder.AbstractProcessBuilder.addConnector(AbstractProcessBuilder.java:109)
org.bonitasoft.studio.engine.export.builder.EngineFlowElementBuilder.handleCommonActivity(EngineFlowElementBuilder.java:704)
org.bonitasoft.studio.engine.export.builder.EngineFlowElementBuilder.caseActivity(EngineFlowElementBuilder.java:152)
org.bonitasoft.studio.engine.export.builder.EngineFlowElementBuilder.caseActivity(EngineFlowElementBuilder.java:1)
org.bonitasoft.studio.model.process.util.ProcessSwitch.doSwitch(ProcessSwitch.java:823)
org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:53)
org.eclipse.emf.ecore.util.Switch.doSwitch(Switch.java:69)
org.bonitasoft.studio.engine.export.DesignProcessDefinitionBuilder.processFlowElements(DesignProcessDefinitionBuilder.java:85)
org.bonitasoft.studio.engine.export.DesignProcessDefinitionBuilder.createDefinition(DesignProcessDefinitionBuilder.java:66)
org.bonitasoft.studio.engine.export.BarExporter.createBusinessArchive(BarExporter.java:92)
org.bonitasoft.studio.engine.export.BarExporter.createBusinessArchive(BarExporter.java:178)
org.bonitasoft.studio.engine.operation.DeployProcessOperation.deployProcess(DeployProcessOperation.java:169)
org.bonitasoft.studio.engine.operation.DeployProcessOperation.deploy(DeployProcessOperation.java:149)
org.bonitasoft.studio.engine.operation.DeployProcessOperation.run(DeployProcessOperation.java:116)
org.bonitasoft.studio.engine.operation.RunProcessOperation.run(RunProcessOperation.java:84)
org.bonitasoft.studio.engine.command.RunProcessCommand$1.run(RunProcessCommand.java:126)
org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)

 

How can I fix the problem?!!!