Hello

1. The problem with 'Spanish translation' App.
It looks like the product wasn't correctly posted in UNA Market. You need to contact with its vendor and ask him to check.

2. The problem with Apps Market > Storefront.
You need to check Key & Secret pair in your Studio -> Settings -> General -> 'UNA account key' and 'UNA account secret' settings. The pair should be registered with correct site URL here in My Sites. 

Best Regards
Anton