Empty graph after opening a shader

Hi !

One of our artist found a strange bug. When opening one of our shader (and only one), the graph is totally empty and we can't add any node.

I tested it on my computer and I have the same issue.

Moreover, he also got an error in the console (I don't have it), which seems to prevent him from opening shader through the inspector (he can only use the open button from the Shader Forge menu).

Shader code is here : http://pastebin.com/T67gEeg2

We're using Shader Forge 1.26 under Unity 5.3.2p3

Many thanks if you can have a look at this.

Robin