那位大虾，请帮忙解释一下这是什么错误，如何解决？
当我导入xpdl文件时，出现如下错误：
2291325[ UtilXml.java:443:ERROR] XmlFileLoader: File file:/c:/ZnjTest
XPDL.xml process error. Line: 131. Error message: Element type "Deadline" must b
e declared.
2291345[ UtilXml.java:443:ERROR] XmlFileLoader: File file:/c:/ZnjTest
XPDL.xml process error. Line: 132. Error message: Element type "DeadlineConditio
n" must be declared.
2291375[ UtilXml.java:443:ERROR] XmlFileLoader: File file:/c:/ZnjTest
XPDL.xml process error. Line: 133. Error message: Element type "ExceptionName" m
ust be declared.
2291385[ UtilXml.java:443:ERROR] XmlFileLoader: File file:/c:/ZnjTest
XPDL.xml process error. Line: 135. Error message: Element type "Deadline" must b
e declared.
2291425[ UtilXml.java:443:ERROR] XmlFileLoader: File file:/c:/ZnjTest
XPDL.xml process error. Line: 136. Error message: Element type "DeadlineConditio
n" must be declared.
2291455[ UtilXml.java:443:ERROR] XmlFileLoader: File file:/c:/ZnjTest
XPDL.xml process error. Line: 137. Error message: Element type "ExceptionName" m
ust be declared.
2291475[ UtilXml.java:443:ERROR] XmlFileLoader: File file:/c:/ZnjTest
XPDL.xml process error. Line: 155. Error message: The content of element type "A
ctivity" must match "(Description?,Limit?,(Route|Implementation),Performer?,Star
tMode?,FinishMode?,Priority?,SimulationInformation?,Icon?,Documentation?,Transit
ionRestrictions?,ExtendedAttributes?)".
在规范中的“最终期限”已经明确的解释，为什么服务器还提示“must be declared”。谢谢！