Feed rejected Error Code: InvalidMarketplace. Error Type: Sender

The error you receive: Feed rejected Error Code: InvalidMarketplace. Error Type: Sender

Description: In most cases, this error is connected to the status of your seller account on the amazon marketplace. Please navigate to a seller central on your amazon marketplace. Please check your seller status (Settings > Account Info). 

It should be "Active". 

Example on the picture:

In certain cases, you can get here an active and valid status but still can't export products.

Then please try to add products via the amazon interface:

1) Catalog > Add Products

2) Select "I'm adding a product not sold on Amazon"

3) Choose one of the amazon category using the category tree

In a normal situation, you should get a new page where you can enter your product details.

If your account has some errors with the configuration you may see the following page:

Please try to "Reactivate Account" and if this didn't help contact amazon seller support.