I've looked through the Wiki, but I cannot find a method to disable jumping.
I've used messy methods like forcing the player in one position, but as I said, messy, and it makes other problems with the physics.
If you have any information on this, even just a reference, I'd most appreciate it.
Thanks.
In just about every instance (if not all), there is an Event called "Changed." When any value or child the instance carries changes in any way, this will activate. To use this to your advantage, jumping will change the Humanoid, so you can use:
humanoid.Changed:connect(function() humanoid.Jump = false end)
Just in case the change to the humanoid was that the player jumped, it will set this to false to make sure that the player can't jump.