YEP -- Seems too? -- I tried it with two different XML Files in that directory. One being the the default XML and my working file. I never get to the stage that I can open a file as it throws an exception immediately -- Again -- version 19 still works fine. I think that at some point version 21 worked with some version of mac also but stopped working with a later release of the op system.
Which is why I think its a security problem which I can't figure out -- But with no help from Graphisoft i am at a disadvantage.
Gerry
Windows 11 - Visual Studio 2022; ArchiCAD 27