In some cases the transactions fail and users get error codes, here are some of the common situations and simple solutions.

    

1. Get error code 400 while making an offer
      - It might happen when the item had been transferred, sold or delisted but still shows up on marketplace due to delayed capture of info on chain.
     - Solution: refresh the item data and try again after a while.
     
2.  Get error code 400 while buying an item 
      - It might happen when the item had been sold or delisted but still shows up on marketplace due to delayed capture of info on chain.
      - Solution: refresh the item data and try again after a while.
     
3. Get error code 400 or order unfulfilled while accepting an offer
      - It might happen when the buyer doesn't have enough balance to fulfill the order.
    
4. Get error code 400 while listing
      - It might happen due to a jam on chain.
      - Solution: refresh the item data and try again after a while.