wrong files title names ( renamed by Mendeley ??)

all my files are written with these titles ??? what I did wrong ? when I transferred they look like this : Sir et al. - 2010 - No Title(437).pdf Sir et al. - 2010 - No Title(438).pdf Sir et al. - 2010 - No Title(439).pdf Sir et al. - 2010 - No Title(440).pdf, etc, etc....... thanks in advance Manuel Garcia MD