Hi, not exactly an error per se, but a bit jarring. The flowers added in the Botany addon do not wave when using a shader, which looks bad when all the vanilla flowers are swaying slightly. It would be a pretty easy fix, if you would just include the block mapping.
Quoted from block.properties in the shader comment-
"#Forge mods may add custom block mapping as "assets/<modid>/shaders/block.properties" in the mod JAR file. #Format "block.<id>=<block1> <block2> ..." #Only one line per block ID is allowed. # Short format #block.31=red_flower yellow_flower reeds # Long format #block.32=minecraft:red_flower ic2:nether_flower botania:reeds # Properties #block.33=minecraft:red_flower:type=white_tulip minecraft:red_flower:type=pink_tulip botania:reeds:type=green # Block ID, Metadata (backwards compatibility) #block.34=38:6 38:7 83"
It just needs to specify the grass/flowers as something that can wave slightly. I've included the block.properties from the optifine shader which has instructions on how to add support in your mod.
Other than that, I love the mod!