使用java itext数字签名pdf

Question

我收到以下错误

  

签名验证期间出错。签名包含不正确，无法识别，已损坏或可疑的数据。支持信息：SigDict /内容非法数据

在此代码中：

            <ObjectPageHeaderContent>
                           <content>
                                           <layout:VerticalLayout>
                                                           <m:ObjectStatus title="User ID" text="12345678"/>
                                                           <m:ObjectStatus title="Functional Area" text="Developement"/>
                                                           <m:ObjectStatus title="Cost Center" text="PI DFA GD Programs and Product"/>
                                                           <m:ObjectStatus title="Email" text="email@address.com"/>
                                           </layout:VerticalLayout>


                                           <layout:VerticalLayout>
                                           <m:Title text="YourHeader" titleStyle="H4"/>
                                           <m:Text width="200px"
                                                                          text="Hi, I'm Denise. I am passionate about what I do and I'll go the extra mile to make the customer win."/>
                                                           <m:ObjectStatus title="Email" text="email@address.com"/>
                                           </layout:VerticalLayout>


                                           <m:ObjectStatus text="In Stock" state="Error"/>

出了什么问题？