Forge version: 14.23.1.2566
Twilight Forest version: build 265+ (starting with commit c88f60d )
Link to crash log: no crash log needed

Steps to reproduce:

1. build water pool with flowers
2. throw diamond into pool

What I expected to happen:
create portal to TF

What happened instead:
nothing

Notes: no other mods installed

Are you playing on a server? Can you take a screenshot of the water?

i am in single player mode

Can you show me the config file?

twilightforest.cfg.txt

i have found the bug.

flowers aren't full blocks (cubes)

Whoops. That was definitely for the isDirtOrGrass method

This was fixed in 9524fe6