replace pdfnet.dll

I am replace the pdfnet.dll to a new version
and when i do it i get error
“PDFNet was already initialized in demo mode. For solution see\n\t Conditional expression: \n\t Filename : \n\t Function : \n\t Linenumber : 0\n”
what i need to do
(?freamwork other)

As the error message suggested, did you take a look at

If you are an existing customer, please get in touch with us via with your license id and more details re: how you are initialising PDFNet.