Ah, that is definitely the issue. Its been repeated time and time again to switch your settings from comma to period due to some issues that may occur. Sadly you cannot refit PDCs, but you can delete the old designs and SM in the new ones.
As I am running Aurora through Wine on Ubuntu it took me some time to figure out how to change the settings for Aurora only and not for the rest of system. And I was more interested in playing more then to figure out. But in the end it is pretty simple, you just
cd
to the folder with Aurora (just adding that folder to PATH may work too) and use
LC_ALL=en_US.UTF-8 wine Aurora.exe
.
to change all your language settings to en_US just for this one command.
And I can refit PDCs. See in Industry, its under "Installations", "Ship components" and so on, the second to last option.