System Information
Windows 10 - Nvidia GTX750 - Driver version 365.10

Blender Version
Broken: 2.77a abf6f08

Short description of error

Node Wrangler Addon - Shift-S changing a nide but throwing an error while doing so

Exact steps for others to reproduce the error
Enable the node wrangler add-on.

Press SHIFT-S to change the diffuse node and change it to something else.

The node changes but I always get the error message in the picture...

Based on a (as simple as possible) attached .blend file with minimum amount of steps