Error code 1511

I was trying to buy a bundle and every time I hit 'accept offer', I would get this message: "Sorry! There was an error while completing this offer. Please try again or contact Poshmark Support for additional help. [Error Code: 1511]". Couldn't figure it out. Google said it was due to the seller blocking me or an item not being available but that wasn't the case. Communicated with the seller and they tried accepting my offer but it wouldn't work. So I just declined the offer and resubmitted it and the issue disappeared. Weird. But I thought I would share in case this helps anyone.