I found a bug in Xojo 2017r1.1 macOS:
When you have a long string with German “Umlaute” [ , , , ]" and split it, it will make a crazy array, but nothing you would expected.
example:
Dim MZZeilen_Adressen(-1) as String = MZString_Adressen.Split(";")
This only happens with 64bit. If I compile to 32bit, everything works.