We haven't changed that part of codebase for a very long time. It would appear that Iridium made a change to their API recently by removing some fields and of course without informing us.
We have identified the missing fields and have reported it to Iridium (PayVector). The issue is caused by preauthorisation in 3D Secure transactions.
Once we have heard from them, we will let you know.
For now, the obvious solution would be to disable 3D Secure if you are using delayed capture.
We hope to have a more sustainable solution as soon as PayVector has contacted us.