I started using the wonderful tcolorbox package in Lyx. As can be seen in the first and second pictures, I added the module "fancy color boxes" in the settings, and then chose "insert" > "custom insets" > "color box".
I also added these commands to the preamble:
\usepackage{tcolorbox}
\usepackage{tikz}
I tried modifying the design of the color box, as can be seen in the following picture:
I added a color box options inset, inside the color box, and wrote a simple command for the title of the box, its background color, and its frame color.
I got the error above. I searched it on the internet, but couldn't find a way to fix it. Does anybody know what is the problem, and how can it be fixed?
thanks in advance


