If when loading your Simplify3D scene (.factory) you get the message “the analysis of the XML file failed…” it is because the STL objects you import into Simplify3D contain special characters. These characters can be accents, symbols or any other character that is not a single letter or number.
We have already reported this bug to the Simplify development firm. But they have no corrections for the moment.
Do not use any characters other than numbers and simple letters, including in process names, for the problem to disappear.