I wonder if you’re hitting the ES2 texture limit (it’s only 8 
). You have 6 textures in your material, the landscape will need one for weights, and I believe static lighting uses another. If I’m forgetting another somewhere then that would put you over the limit.
Does it say why it failed to compile?
EDIT: The docs say you can only use 5 textures on mobile, so having 6 in your material is probably the issue.