bulk_get_inventory_item returns error: Failed to transform underlying error response, see logs

[skullcandy]

I am trying to get an inventory item in my eBay store using the Inventory API's /bulk_get_inventory_item endpoint, but I keep getting a 500 error from eBay. I'm using a Rails app.

The request I am sending is as follows:

Rest Call

RestClient.post(api_uri, payload, headers)

api_uri

https://api.ebay.com/sell/inventory/v1/bulk_get_inventory_item

payload

{"requests":[{"sku":"#{item_sku}"}]} # json object

headers  

{:Authorization=>"Bearer #{our bearer token}","Content-Type"=>"application/json"}

 
The error I am getting is:

{"errors": [{
"errorId": 2003,
"domain": "ACCESS",
"category": "APPLICATION",
"message": "Internal error",
"longMessage": "There was a problem with an eBay internal system orprocess. Contact eBay developer support for assistance",
"parameters": [{
"name": "reason",
"value": "Failed to transform underlying error response, see logs."
}]
}]}

As far as I can see, I'm following the docs exactly.

I'm currently waiting on a response from my eBay contact, but I figured I'd ask the community if anyone knows how to get past this. Thank you for your help!