Bios error code - Undefined event code 0x0380838c for 15-7577

When I connect my TB16 dock to my 15-7577 laptop I am getting a bios event code. This combination should be supported, but I can't find any info on the code being shown in the bios.

Can anyone tell me what Undefined event code 0x0380838c means?

I can't find reference to it anywhere. The code is generated before the OS loads, so I don't think it is OS related.