Hello
This can happen for a great number of reasons, most of them pertaining to the limitations of the Windows command interpreter. For example, if your project contains files whose full extended path is longer than 260 characters, the command interpreter will fail, so to work this around users are recommended to put their Xcode project in C:\iOS which is a very short starting path. There are, however, other possible causes. Forbidden characters in passwords, that are interpreted by the Windows command interpreter as control characters (!, ^, %) or directory separators (\, /) are another common cause. You might be in one of these cases.
Generally speaking, as politically incorrect as it sounds, negligence to follow the advices given in the various message boxes that appear during the program use, and the warnings given in the documentation, are the root cause of such problems. These warnings and advices are probably not exhaustive, and you might have run into an undocumented case, but they do cover a great lot of these cases already, so make sure you followed them all.