Other button clicks works on the game. I am able to move the camera, click on the mini map, collect gold, and pause the game. For some reason I cannot click on the building blocks.
Cannot check on a regression since 4.13 cannot load the game in the browser, but it is safe to say it is a regression.
Result: Unable to click to build a tower
Expected: Able to click on the block that opens the building UI
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-38357 in the post.