In case of you have added the reference to the PdfMetamorphosis.dll by the old way (Solution Explorer->right click by "References"->Add Reference...), please add these dependencies using NuGet:

    <PackageReference Include="Pkcs11Interop" Version="5.1.2" />
    <PackageReference Include="Portable.BouncyCastle" Version="1.9.0" />
    <PackageReference Include="SkiaSharp" Version="2.88.7" />
    <PackageReference Include="SkiaSharp.HarfBuzz" Version="2.88.7" />
    <PackageReference Include="Svg.Skia" Version="1.0.0.18" />
    <PackageReference Include="System.IO.Packaging" Version="4.5.0" />
    <PackageReference Include="System.Text.Encoding.CodePages" Version="4.5.0" />
	<PackageReference Include="SkiaSharp.NativeAssets.Linux" Version="2.88.7" />
	<PackageReference Include="SkiaSharp.NativeAssets.macOS" Version="2.88.7" />

For example, to add "System.IO.Packaging, 4.5.0:
(Solution Explorer->right click by "References"->Manage Nuget Packages...->In the tab "Browse" type "System.IO.Packaging" and find the "System.IO.Packaging", select version "4.5.0").

Detailed steps:
https://sautinsoft.com/products/pdf-metamorphosis/help/net/getting-started/windows.php

If you will have any questions, please don't hesitate to email us at: support@sautinsoft.com!