Trying to use SwiPlCs in C# app

Help! PlDoc
1

Hello there!

I’m trying to include SwiPlCs in my net7.0 project.

When I put this in my .csproj

<Reference Include="SwiPlCs">
    <HintPath>lib\SwiPlCs.dll</HintPath>
</Reference>

I get:

Unhandled exception. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at System.Runtime.InteropServices.Marshal.WriteInt64(IntPtr ptr, Int32 ofs, Int64 val)
   at SbsSW.SwiPlCs.libpl.SetStreamFunction(PlStreamType streamType, StreamsFunction functionType, Delegate function)
   at SbsSW.SwiPlCs.PlEngine.SetStreamFunctionWrite(PlStreamType streamType, DelegateStreamWriteFunction function)
   at SbsSW.SwiPlCs.PlEngine.Initialize(String[] argv)
   at Program.<Main>$(String[] args) in \path\to\Program.cs:line 42

if I try this:

<Reference Include="SwiPlCs64">
  <HintPath>lib\SwiPlCs64.dll</HintPath>
</Reference>

I get this:

Unhandled exception. System.IO.FileNotFoundException: Could not load file or assembly 'SwiPlCs, Version=1.1.60601.0, Culture=neutral, PublicKeyToken=03ea137181587c56'. The system cannot find the file 
specified.
File name: 'SwiPlCs, Version=1.1.60601.0, Culture=neutral, PublicKeyToken=03ea137181587c56'
   at Program.<Main>$(String[] args)

Is there any reason this shouldn’t work? Suggestions would be much appreciated!