1. I go to spine-runtimes github page and download as zip.
2. I extract the spine-runtime-4.2 folder to my desktop.
3. I go to spine-ts/spine-canvas/example.
4. I double click on index.html which opens up my browser Firefox.
5. Nothing shows up, it is completely blank browser window.
   What am I doing wrong here? I'm so confused.

I repeat with a bunch of other html example files, some of them are blank, some of them have text but nothing else. Same thing happens when i open in Microsoft Edge.