The invoked member is not supported in a dynamic assembly

Ok here is my problem. On my server I have all the .dll I need for my Web Project (.asp net). I have my project .dll and other external .dll (and ceTe.DynamicPDF.20.dll). My Project is in .Net 4.0.

So when I build my web project and I replace (on the server) the old .dll of my project with the new that was built and I try to generate a  PDF I got the error :

The invoked member is not supported in a dynamic assembly

[NotSupportedException: The invoked member is not supported in a dynamic assembly.]
   System.Reflection.Emit.InternalAssemblyBuilder.GetManifestResourceNames() +56
   zz93.a5.a() +422
   zz93.a5..cctor() +375

I get it that I am not one the same .net framework BUT, if before generating a PDF with the new .dll of my project, I replace the ceTe.DynamicPDF.20.dll with the SAME .dll, everything works fine.

Can you help me with that?
Thank you.

And it also works when I update my project .dll and I restart my IIS.

Hello,

ceTe.DynamicPDF.20.dll is intended to be used with .NET 2.0 projects, using it with other framework versions may cause unpredictable behavior similar to what you are experiencing.  Here is the link to list of .NET dlls provided with DynamicPDF v5 and their target framework versions. 

We have added support for .NET 4.0 in later versions and DynamicPDF v7 supports .NET 4.0. Here is the documentation link for v7. You can download the evaluation edition of version 7 here.

Thanks,
ceTe Software Support Team.