Describe the bug
Item stacks are decremented in a way that can result in stacks of zero that cause machines to spam error notifications. No errors, warnings, or trace logs are generated from this. I'm told that there were specific vanilla methods added with 1.6 for reducing stack sizes that should have replaced this. Direct link to the suspected code

To Reproduce
Exact steps which reproduce the bug, if possible. For example:

1. Place a mayonnaise machine next to a chest.
2. Place an egg of any quality in the chest.
3. Watch as the machine begins and the egg stack persists with 0 items in it (you can verify by using the book that lets you see sell price on stacks, it will show as being worth 0).
4. When the machine finishes, the notification in the image will be produced repeatedly as the machine scans the inventory, fails to grab the 0-stack, and tries again.

Log file
Upload your SMAPI log to https://smapi.io/log and post a link here.

Screenshots

Saw you and Digus discussing this the other day, sounded like the root cause may have been PFM.