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Compare documents with temporary license applied in .NET

On Windows 10, 64 bit… Visual Studio 2017 Community Edition with all updates applied.

I got the Example project from GitHub:

git clone

Loaded solution into Visual Studio 2017.

Uncommented out the first example in Program.cs:


Left everything else alone in Program.cs.

When I run it the result of comparison.Compare is null causing an exception…

I tried uncommenting some of the other examples instead and they also have the same problem.

I then obtained a trial license and uncommented the lines that apply it but still getting the same problem with comparison.Compare() returning null.

It does take a second or two when I step over the Compare() function when using the stream methods, but just returns null every time.

The project from GitHub references version 19.3.1 of GroupDocs.Comparison from NuGet. I also tried downgrading to older versions of the Nuget package with the same results.

Actually it is now working with the trial license (I’d accidentally used one from another GroupDocs product), but I would still have expected it to work in unlicensed mode without a license as I am in very early stages of evaluating this to see if it will be useful to our project in the next few months and didn’t really want to start a 30 day trial until later on in development.

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We’d like to update you about API evaluation limitations. Please go through this article. Regarding PDF documents, they should not have more then four elements of any collection otherwise you will get null results. However, if you compare two small PDF documents (e.g. 1 paged files) without licence, you will still get trial badge in the output.
See this result - output.JPG (46.6 KB)