I'm getting an internal application error (10007) when trying to addFixedPriceItem via the trading api. I thought maybe this was me, so I went to the API explorer and got it there: https://developer.ebay.com/DevZone/build-test/test-tool/?index=0&api=trading&call=AddFixedPriceItem&variation=xml
At first in the API explorer, I got a listing duration error, but I changed the listing duration to GTC. Then I get the 10007 error, just like when I make the call via the API. Maybe it's something to do with my user? I changed nothing else about the API explorer call other than putting in my auth token. I have changed my sandbox account to be a seller account. Ebay sandbox account is davidbankes+ebaytest@gmail.com. (I also have a pending request to link my paypal sandbox account, but I don't think that's the issue.)