I wish I could fix this mod, but sadly I don't know what the issue is. I'm talking about the
Custom Crop Decay mod by ZaneYork. I believe the 1.5 update broke it, the code is
here on Github. The mod's page is
here.
It is the only mod, that I am aware of, that allows for crops to spoil and expire. I really really love this addition to gameplay, really adds a very interesting challenge to Stardew.
SMAPI shows the mod as working, but it definitely is dead. It seems to load, at the very least there are no errors, but it affects nothing at all. I clearly remember it working when I played about 1.5 years ago.
Ok Edit; Apparently it does work? Initially, I applied the mod on a persistent save. It did not work, but SMAPI showed nothing out of the ordinary. After restarting, I created a new save file. This time it DID work. I tested it quite a bit, skipping through days and months, seeing if something is up. Turns out, everything does work like it is supposed to, at least from my short testing. Items indeed decay, I set the value to 3 days, and no matter how I added and removed items, the decay was persistent and there were no issues. Well I noticed one thing to keep in mind, if you have a crop with decay in the inventory and you aquire a new one, that crop will inherit the decay value of the current crop in the inventory. What I did then was load my other save, where the mod initially did not work, and tried it there again, now it also seems to work here too.
I guess this problem is solved then? I do have the unofficial PYTK mod too. I shall write my experience on the Nexus website.