So what's happening is Water-Friendly-Walls-Fix sets the "water_connection_patch" value of all walls to "nil" on condition of the startup setting "shallow-water-walls-water-connect" being false in its settings, which always happens by default but adding this mod to the mix shifts the load order around (due to it being a dependency for Dectorio Fixes) to make it an issue.
In the normal load order without this mod Dectorio Fixes will probably load before Water-Friendly-Walls-Fix so it can access the value it needs before it is set to nil. But since Dectorio Fixes has this mod as an optional dependency, it will want to load after this mod, and wherever this mod may be ends up after Water-Friendly-Walls-Fix meaning Dectorio Fixes now loads that value after it becomes nil, and doesn't know how to deal with it.
This could be fixed by Dectorio fixes having a nil check added, or by having Water-Friendly-Walls-Fix have Dectorio fork as an optional dependency to make it load after. I tested the latter solution and found that the game will launch that way.
Ideally, one of the other devs will implement a solution but if they are MIA you can manually add Dectorio fork as a dependency for Water-Friendly-Walls-Fix by editing the info.json in Water-Friendly-Walls-Fix and adding "? dectorio-fixes" to the dependency array (make sure to add a comma after the previous entry too if it doesn't have one).
