Greengage leaves have developed a thick brown margin which then yellows towards the centre of the leaf, and they are dryish.
We had plenty of fruit this year (which was fine and tasty)and no other problems. The veins remain green in the centre of the leaf!
Certified GKH Gardening Expert
This could be a number of things. If the crop was fine, then I would be inclined to say that it could be a simple nutrient deficiency. If you are not thinning the tree, it can become too heavy with fruit, cause crowding and disease. See the cultural requirements below.