Saw this happening just now. Since it still worked a couple of weeks ago, I think they changed something backwards incompatible to the API.
The calls are still going through, since I can see the following on my API page:
"You have used 4 requests in the last hour for API Path '/volume' (reset in 51 minutes)".
"ERROR OCCURRED CONTACTING COMICVINE. RETRYING..."
Saw this happening just now. Since it still worked a couple of weeks ago, I think they changed something backwards incompatible to the API.
The calls are still going through, since I can see the following on my API page: "You have used 4 requests in the last hour for API Path '/volume' (reset in 51 minutes)".
Could you perhaps take a look?