Saxon

This is a follow-up to the closed https://saxonica.plan.io/issues/5122, I have now tried to use fn:highest with the latest SaxonCS 11.1 on Windows but an attempt to use that function in XSLT 4 fails with Saxon.Api.SaxonApiException, Failed to load built-in function library: function-library.sef.xml.

Saxon.Api.SaxonApiException
  HResult=0x80131500
  Nachricht = Failed to load built-in function library: function-library.sef.xml
  Quelle = SaxonCS
  Stapelüberwachung:
   at Saxon.Hej.s9api.Xslt30Transformer.callTemplate(QName templateName, Destination destination)
   at Saxon.Api.Xslt30Transformer.CallTemplate(QName templateName, IDestination destination)
   at SaxonCSRunXSLT4.Program.Main(String[] args) in C:\Users\marti\source\repos\SaxonCSRunXSLT4\SaxonCSRunXSLT4\Program.cs:line 37

C# test code

using System;
using System.IO;
using Saxon.Api;

namespace SaxonCSRunXSLT4
{
    class Program
    {
        static void Main(string[] args)
        {
            var processor = new Processor();

            //processor.SetProperty<bool>(Feature<bool>.TIMING, true);

            var xsltCompiler = processor.NewXsltCompiler();

            xsltCompiler.XsltLanguageVersion = "4.0";

            XsltExecutable xsltExecutable;

            using (var fs = File.OpenRead(args[0]))
            {
                xsltExecutable = xsltCompiler.Compile(fs);
            }

            Xslt30Transformer xslt40Transformer = xsltExecutable.Load30();

            if (args.Length == 2)
            {
                using (var fs = File.OpenRead(args[1]))
                {
                    xslt40Transformer.ApplyTemplates(fs, processor.NewSerializer(Console.Out));
                }
            }
            else
            {
                xslt40Transformer.CallTemplate(null, processor.NewSerializer(Console.Out));
            }
        
            Console.WriteLine();
        }
    }
}

runs file highest-function-test1.xsl:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version="4.0"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    exclude-result-prefixes="#all"
    expand-text="yes">
    
    <xsl:output method="adaptive" indent="yes" build-tree="no"/>
    
    <xsl:template match="/" name="xsl:initial-template">
        <xsl:sequence select="highest((1, 2, 3, 3, 2, 1))"/>
    </xsl:template>
    
</xsl:stylesheet>