An unknown Exception was thrown

System.Exception: Unable to get a .NET type named [Altiris.TaskManagement.Common.Tokens.TokenDefinitionCollection, Altiris.TaskManagement.Common, Version=7.5.3193.0, Culture=neutral, PublicKeyToken=99b1e4cc0d03f223] at Altiris.DotNetLib.Collections.ParamInfo.ToValue() at Altiris.DotNetLib.Collections.SerializedParameterCollection.ToParameterValueCollection() at Altiris.ClientTask.Server.Data.ClientTaskServerExecutionInstance.get_InputParameterValues() at Altiris.ClientTask.Server.Execution.ClientTaskEngineExecutionThread.LoadInputParametersFromTaskInstanceParent() at Altiris.ClientTask.Server.Execution.ClientTaskEngineExecutionThread.Execute() at Altiris.TaskManagement.Common.Execution.Engine.TaskExecutionEngine.ProcessTaskExecuteOperation(TaskInstanceRequest request, TaskEngineExecutionThread thread)