What is wrong with my yellowing cedar elm tree?

Question

The leaves have a red spotted “measles”, all over them. The center vein of each leaf is still somewhat green. The entire tree is affected.

Answer 1

It likely has a fungal infection. Here is more:
https://www.gardeningknowhow.com/ornamental/trees/elm/diseases-of-elm-trees.htm

If the spots are bumps, it could be leaf gall:
https://www.gardeningknowhow.com/plant-problems/environmental/treating-leaf-gall-on-plants.htm