Thanks for looking at it! Good luck on your future mining projects!
Hmm. Nope. Switching to 1.5.57 didn't change anything.
Here's the log up until the big error, repeat, error, repeat.
Starting… [2018-03-08 20:57:50] Started bfgminer 5.4.2-unknown
[2018-03-08 20:57:50] Loaded configuration …
I was using the one in MacMiner. I'll let you know about 1.5.57
I'm on 10.13.3, and I have a Nvidia GTX 970
bfgminer for Mac OS X, and I was running the Scrypt algorithm.