[Marketplace Errors when Uploading]

Keep getting errors when trying to upload a product to Marketplace. I cant send my stuffs to marketplace to sell them, the window where i drop the stuffs isnt opening for me. Is there a fix for this, says the store is returning erros.

[Marketplace error]

My marketplace is giving an error 410, i just cant send new stuffs to sell at my store, it says is not possible now and i will have to try later. Its gonna be one week with this problem. anybody help me pls?

[Merchant Outbox]

Im having the same problem at my marketplace, doenst work anymore, i cant sell the stuffs to there. pls someone help me?