Based on the error it seems that you are missing standard VC Redistributable on the targer server.
For more info, please see https://groups.google.com/d/topic/pdfnet-sdk/OqVycSlOlB0/discussion
If this does not helps:
a) If you are suing .NET 4, you should use PDFNet for .NET 4 and not version for 2-3.5
b) If you are using Any CPU project setting you need to make sure that you are using 64-bit version of PDFNet (i.e. it should match address space 32/ vs 64 bit of the containing process - https://groups.google.com/d/topic/pdfnet-sdk/Op5m-2VH2ww/discussion).