Wither skulls stopped selling to the server.

Upon entering the command /sell hand you get the error message
"Trying to sell more items than are available"

This item is one of the theme items worth $100 each which has resulted in @MichaelE100 and myself wasting a week in vmr with no progress since reset is in 45 mins,

EDIT
I found that I had a skull on my head and that was what was stopping the sale.