Enzo,
The first error "File I/O Error: Unable to open file" seems to suggest that perhaps you need to put quotes around the complete path due to the space in the path name (the one between the "Pleiades Astrophoto" part of the path). You have to do this in on a windows command prompt, so perhaps you have to do the same in PI.
I've no idea if this will work mind, but if not i'm sure one of the PI team will step in to help you out!
Cheers,
Simon.