我正在使用 alfresco 社区版及其 activiti 工作流引擎。我想在我的 java 类中访问 activiti 任务和执行；设置并获取一些变量。但是RuntimeService有一个问题，调用它的方法时会抛出异常：
org.activiti.engine.ProcessEngine.getRuntimeService().getVariables(taskExecutionId))
它抛出：
org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: org.activiti.engine.ActivitiException: unknown variable type name alfrescoScriptNode
### The error may involve org.activiti.engine.impl.persistence.entity.VariableInstanceEntity.selectVariablesByExecutionId-Inline
### The error occurred while setting parameters
### Cause: org.activiti.engine.ActivitiException: unknown variable type name alfrescoScriptNode
at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:8)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:77)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:69)
at org.activiti.engine.impl.db.DbSqlSession.selectList(DbSqlSession.java:182)
at org.activiti.engine.impl.persistence.entity.VariableInstanceManager.findVariableInstancesByExecutionId(VariableInstanceManager.java:47)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.loadVariableInstances(ExecutionEntity.java:880)
at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.ensureVariableInstancesInitialized(VariableScopeImpl.java:57)
at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.collectVariables(VariableScopeImpl.java:78)
at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.getVariables(VariableScopeImpl.java:65)
at org.activiti.engine.impl.cmd.GetExecutionVariablesCmd.execute(GetExecutionVariablesCmd.java:58)
at org.activiti.engine.impl.cmd.GetExecutionVariablesCmd.execute(GetExecutionVariablesCmd.java:28)
at org.activiti.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:24)
at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:42)
at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33)
at org.activiti.engine.impl.RuntimeServiceImpl.getVariables(RuntimeServiceImpl.java:81)
我搜索了它，但没有相关结果。