I am writing a SharePoint item event receiver to OCR documents that are uploaded/added to a library to generate searchable PDF for that document. I'm using a third party library (dll) "tesseract.net.sdk" to convert the input pdf to searchable pdf.

I am using visual studio 2015 for sandbox solution deployment to a SharePoint 2010 farm. I have added the external library (dll) using the package external assemblies option but when I try to deploy the project it gives following error:

Could not load file or assembly C:\Users\test.user\AppData\Local\Temp\solution-3a181ba8-d203-45c8-8567-c3b0b459ef32\cab\tesseract.dll or one of its dependencies. The module was expected to contain an assembly manifest."

The exact Windows dll is having a problem with is the tesseract.dll.

Please let me know how can I add this dll to my package (wsp) and correct the error I'm encountering.

1 Answer 1


Open package.package , in the bottom switch to advanced tab. Click add. Below screen will popup. Fill the required details.


This way,you can add external assemblies to your wsp.

This post will help to understand more.

  • Thanks , But i already tried this way only ...Although i am able to add one external assembly "Patagames.ocr.dll" but as i said "tesseract.dll" is an naive library so i guess i am facing issue ... Jan 13, 2016 at 6:55
  • You faced this issue while adding external assemblies only right ? and you tried adding it the way I suggested, Jan 13, 2016 at 7:03
  • 1
    Yes , I am adding library in same manner , facing the issue while i am deploying my project (sandbox) to my share point site , as my project have dependencies of two libraries "patagames.ocr.dll" and "tesseract.dll" and one data folder "tessdata" (contains language cubes/traindata files ) . Jan 13, 2016 at 7:11

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.