kicked me out

i was downloading a texture pack named "Mojokraft v.7". i put both texture packs in the 2nd box and pressed: Use texture packs. then it kicked me out telling me i have a crash report. they say i should delete the texture pack and all. and i was deleting it. then i came upon some file called :#Nether. in the texture pack file. when i tried deleting it then it told me: Can't delete this file or something like that. so i need help!