Free Support Forum -

Licencing issue when using Groupdocs.Web.Annotation.dll version 2.1.1

Good morning,

I am writing on behalf of the company I am working with.
We currently are working with Groupdocs.Web.Annotation.dll version 2.1.1, and are utilising the Viewer class to configure aspects of the GroupDocs viewer within an MVC.Net (

The viewer works fine and renders PDFs as required within our product, however we are constantly prompted that we are running under a trail licence of the product, despite having a valid licence file.
I have confirmed that the licence file is being referenced correctly, and the file path given is correct.

The licence file is referenced by:
Where the licence file path has been pre-validated as being present on disk.

A new validation check has been added: Viewer.IsLicensed, which always returns false. When rendered, the document viewer is rendered with an orange toolbar which indicates that the viewer is being under a trial licence.

After opening and checking the licence file (as it was not me that purchased this licence), I can confirm the following, which I am hoping will be of some use in answering my query:

Developer OEM
GroupDocs.Viewer for .NET

The only think I can think of is that the version of .web. and that of the licence is different. After updating to use GroupDocs.Viewer 3.0.0, I have come across a number of issues, including that I am unable to find a reference to the Viewer class - which I have noted as being removed in version 3.0.0. Unfortunately, we are not authorised to alter too much of the existing code, given that it "works" (management joy).

Are you able to shed any light into this situation and offer any advise on how to proceed?

Many thanks,

Hi Mike,

Thanks for using GroupDocs APIs.

In fact, the next generation GroupDocs.Viewer for .NET, starting from version 3.0.0, is a standalone, back-end document rendering API in which front end UI has been disintegrated. It will require you to create your own front end application to view the rendered documents. The code and the namespaces are also revamped in the next generation versions. You can not use the latest version of GroupDocs.Viewer with the old version of the code and therefore you are getting the reference issues.

Please tell us the version of GroupDocs.Viewer for .NET for which you are getting the licensing issue? We shall be looking forward to your response.

Warm Regards

Good afternoon,

Thank you for your reply.
Currently the only referenced assembly within the solution is:

// Type: Groupdocs.Web.UI.Viewer
// Assembly: Groupdocs.Web.Annotation, Version=

This dll is used to both configure and render the documents on the front end via the extension:

new MemoryStream(Model.DocumentModel.DocumentBytes),

Thank you for your continued support,

Hi Mike,

Thank you for these details. You use a very old version of the library which is not supported by the license you have, please download this version and try to use it. Don’t forget to clean the application and rebuild it after updating the dll. Make sure that your application will use it in run time instead of your current library.

Also I want to notify you that even the version of the library that I shared with you is not supported any more and if possible you should migrate to the latest version.

Best regards.

Worked perfectly many thanks!

I will relay the concerns over the version in use.

Many thanks for your support.

Hi Mike,

You are welcome.

Best regards.