error - Template is not exists

I have created a custom template base-kickstart.java in ~/.config/nvim/templates:

import java.util.Scanner;

public class {{_name_}}{
  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    int T = Integer.parseInt(input.nextLine());
		for (int ks = 1; ks <= T; ks++) {
			{{_cursor_}}
		}
    input.close();
  }
}

and added

let g:sonictemplate_vim_template_dir='~/.config/nvim/templates'

to init.vim. When I create a new file (:e test.java) and then :Template and press tab, I get kickstart in the tab completion.

However when I select it, I get Template kickstart is not exists.

Reproduce the issue with init.vim setting g:sonictemplate_vim_template_dir and the Java template under ~/.config/nvim/templates. Start by tracing the :Template completion and template lookup paths to see why kickstart is listed but cannot be selected. Done means the custom Java template is found and applied successfully.