validate textanchors

Hello Team, I have the following scenario: I am trying to create a Package with a PDF document, which is provided as binary stream. I also want to add a Signer(s) Signature(s) and to locate these through corresponding text-anchors. In case when the required text-anchors are not available in th ePDF document I get the following Error:

com.silanis.esl.sdk.internal.EslServerException: Could not upload document to package. 

Exception: HTTP POST on URI https://sandbox.esignlive.com/packages/qYSDX1Frsvn5-T-F8Hg39g5fWm4=/documents 
resulted in response with status code: [400, Bad Request].