RegisterPackage works for .NET 6, buts fails in .NET 4.5.1

[tpkurilla]

I'm calling some static C# functions from Lua. This code works in .NET 6, but fails in 4.5.1:

        var lua = new Neo.IronLua.Lua();
        LuaGlobal g = lua.CreateEnvironment();
        var localScope = new LuaTable();
        localScope["__metatable"] = new LuaTable();
        localScope.MetaTable["__index"] = g;
        g.RegisterPackage("alg", typeof(LuaAlg));
        var chunk1 = lua.CompileChunk("return 0", "return.lua", null);
        var result1 = g.DoChunk(chunk1);
        var chunk3 = lua.CompileChunk("return test", "ret-test", null);
        var result3 = chunk3.Run(localScope, null);
        var ch4 = lua.CompileChunk("lat, lon, hgt = alg.EFGtoLLH(0.0,0.0,0.0); return llh", "llh-test", null);
        var res4 = ch4.Run(localScope);

I thought it might be due to my targeting 4.7.2. So I added a 4.7.2 target to neolua, and get the same result.

Do the Framework DLLs have some specific thing I need to do to get it to work?

Again, same code (even calling the 4.7.2 library) works when using .NET 6 target, but fails for any Framework target.

Any suggestions?

[neolithos]

Is there any exception? The definition of LuaAlg is missing. May be there is something?