Thanks for the fast answer,
<A target address has caused a fatal exception error> fits best, imho.
It occurs with every file I try to open, no matter if itīs stock or modded, *.dat, *.sim, *.zon, *.dsd, ... It pops immediately after I press the OK button.
BTW, netframework 3.0 is installed.
Renamed the folder, as suggested, but to no avail. V0.54 is still around somewhere. Thanks for asking. So, donīt worry.
Regards,
DD