Material World Position Issue

hi there,

I was following a tutorial about world position materials because i need it for a project that i make. In this tutorial, the instructor is using 2 nodes,a world Position node and a PixelNormalWS node. The material works fine as long i have only connected the world position node. However, the instructor is using the pixelnormalws node.so he can have seamless material in all axes(x,y,z). When i do the same and i connect both nodes into the textures, I get an error in the pixelnormalws node, and in the “if” nodes that it requires. The errors that i got are :

[SM5](Node PixelNormalWS) Invalid node PixelNormalWS used for Normal input.
[SM5](Node if) if Input B must be of type float.

I have provided images to check it out. Any help will be appreciated.