Hen comb turning dark and shrivelling, legs seem weak she is an older hen probably around 3 or 4 years old

[Frugalrooster]

I had a hen die last week but her comb was not dark and she showed no signs of trauma

 

[Wyorp Rock]

Welcome To BYC

Sorry you had a hen die, do you currently have another that is not well?

What do you feed, including treats?

 

[Frugalrooster]

Welcome To BYC

Sorry you had a hen die, do you currently have another that is not well?

What do you feed, including treats?

Yes the one in the picture is the one that is not well the one that died didn’t show any signs of being sick. I have not changed their food. My layer mash comes from the local farmers co-op. So does the scratch grain and black oil sunflower seed

 

[Wyorp Rock]

When was her last egg?

I'd check to make sure her crop is emptying overnight. Look her over for parasites. Consider getting a fecal float to see if worms are part of the issue.
Sometimes hens combs will darken when they are having reproductive problems. Unfortunately, cancer, eyp and other problems seem to be common.