as for earlier i did the same as you told wiped the data and dalvik cache before flashing the file and after flashing it,but after it failed to flashed the file i was unable to boot into cm and it was stuck on cm logo,i'm upgrading my twrp to to squid'2s ,will share results ...thanks for the assistance mate
EDIT : SHOULD I flash the fastboot way or should i go with the twrp flashing ? for the radio files
EDIT2: there's a little issue ,i flashed the squid2's twrp all went good,and since my cm 14.1 wasn't booting i decided to clean flash it again,but as i went into wipe>format data and selected "yes" it gives me this error " unknown file system 'auto' unable to format to remove encryption" i can't believe my luck

, but i still went ahead and from advanced wipe selected everything except for micro sd card, and it flashed the rom successfully .....can you tell me what does this error signify ? and how can i repair it?
edit: i flashed the radio files too it gave me same the error as before..