I can't notate my "Crash cymbal". 😡

For some reason I can't seem to be able to notate my "Crash cymbal". I was able to notate my piano and tympani just fine, but now I can't enter a note onto my "Crash cymbal" bar. (I even changed the notehead to an X and tried to notate it as a quarter-note; though I'd prefer it as an eighth.) What's going on?