Hi RtX,

I tested your code and it worked for me on Zen Cart 1.3.6. Have you tried re-uploading the file and testing it again? From what I can see, there's no syntax error in the code you have provided.

I will be updating my module contributions for version 1.3.8 over the next week or so. At the same time, I will check to make sure the custom sidebox code still works for 1.3.8.