SetValue to Form by using Adobe Workbench

Hi All,

first I'm pretty new to the Adobe Workbench universe. So im still figuring out how everything works.

I try to add a string value by using a SetValue action, to a field which is provided by a simple PDF form. First I read the document from filesystem and then i try to set the value by using XPath Mapping like this:

Location                                                  Expression

/process_data/@Doc/TextField1               'Test'

"TextField1" ist the name of my field within the PDF form (Doc).

But I always get the following error:

ALC-DSC-099-000: com.adobe.idp.dsc.DSCRuntimeException: com.adobe.workflow.WorkflowRuntimeException: Invalid location: /process_data/@Doc/TextField1 cannot be stored for action instance: -1

Can anyone help me to get that running? I'll add some screenshots of my Workbench.

I really appreciate any help you can provide!

Tim