error while converting jpg file to bmp file to import in NAV 2009 R2 classic client

0602.errorGWS.PNG

i want to convert the jpg file to bmp file to make it visible in NAV 2009 RW classic client forms. i dont have any problem doing so in my local computer but when i place the jpg files in the server and try to do same it shows this error. can anyone help me to understand this error??

Thanks

Suman