How to open template map?

How do I open the template map?
I can find them when I browse the OMSI folder normally. but when I browse the folder with OMSI-Editor it just can't find anything eventhough there is a .map file. Do I need to reinstall or is there a fix for this? It just gives me errors if I type the name of the file into the "Open"-box.

We just want to release an english SDK where everything is documentated!