Here are some of the actions that a transaction might fail for:
Minting an item: If your transaction failed during minting an item, most likely either you are using the wrong address in your wallet and you are not the creator of the store. If you are the creator of the store and using the same address - then most likely you already minted the token you are trying to mint. If you have multiple tabs open and try to mint tokens back to back, you will run into this error. You can only mint a token once, so if you made token number 5 already - you can't make another that is also token 5.
Listing an item for sale: If your transaction failed during listing an item, then there was probably an issue with approving the marketplace to sell your item. You can try again by going to "sell an item in my wallet" from the sell page. If you have multiple problems listing an item for sale, reach out to us via support with your transaction hash of the failed transaction.
Listing your domain for sale: If your transaction failed while approving a domain for sale or listing it for sale, most likely you are using the wrong address/not the owner of the domain. If you are the owner of the domain and it still failed, then please reach out to support and we can help you out.
Creating a store: Your transaction should rarely fail when creating a store. If it does, please reach out to support with your transaction hash and we will look into whats going on.
Buying an item: If your transaction failed while buying an item, it means that item has already been purchased. If this happens on more than 1 item or the item says its for sale but this happens, please link the item on discord/email support with the item link and we will look into it.