Material Theme is my favorite Sublime Text theme. It released its version 4 recently. One of the major changes is Material Theme no longer uses its own file icon, replacing it with zz File Icon.

A problem I have is the icons use in Material Theme is unstable. Sometimes it uses the zz File Icon and sometimes it uses its own icons.

A solution to this problem is to force the icon override in the zz File Icon.

The instruction is Preferences -> Package Settings -> File Icons -> Settings and add the force_override to true.

{
	"force_override": true,
}

Happy coding.