PDFSharp Error: Invalid entry in XRef table

This the error i am getting in c# PDFsharp version 1.50.5147

It was worked last year now i am getting the error

Invalid entry in XRef table, ID=3, Generation=0, Position=15, ID of referenced object=5, Generation of referenced object=0

public static int GetNumberOfPdfPages(Stream stream)
{
    int PageCount = 0;
    stream.Position = 0;
    PdfDocument document = PdfReader.Open(stream);
    
     
    PageCount = document.PageCount;
    return PageCount;
}

Kindly suggest