Customizable adhesion test

I will not claim to have invented this category of tools. But since I have multiple printers, different sizes and shapes I wanted to have a simple tool to create adhesion tests.

I have browsed thingiverse for inspiration, and some wants to use circle pads for testing others want to use squares. With this tool you can also make stars :)

Question for the experts: I have tried to enable the customizer, but I get an error when trying to use it. Is it "just" a server error, or have I done something wrong?