Thanks for the suggestions, but they didn't do a thing.
but thanks to your ideas, I found the error!
The reason why the Map Editor couldn't add systems is because the Systemnames lists I used weren't alphabetized.
When I switched my un-alphabetized systemnames list that I use for all my mods with an alphabetized systemnames list from the Devnull Mod (The only one that succeeded in adding systems manually), the error was gone!
That leaves only one question:
Does anybody know a software that organizes words alphabetically?
[ June 13, 2003, 03:07: Message edited by: TerranC ]