Description of the Bug
Fluidlogged API v1.9.0.6 and Railcraft v12.0.0 conflict and cause the bottles to turn into uncraftable potion when picking up water.

To Reproduce
Craft bottle, right click water with both mods installed.

Expected behavior
Water bottle, not uncraftable potion.

Additional context
Tekxit 3.14 v1.0.91

Other mods report here jbredwards/Fluidlogged-API#148
Additional research info here jbredwards/Fluidlogged-API#113

While this is not a real fix you can set B:handleBottles to false in railcraft/railcraft.cfg to get around the issue.