Can't drop in ANY .mca file into chunk viewer on ANY browser

[ynnarg]

I cannot upload/drag in any .mca files on any browser into the Minecraft chunk viewer. I get the following error:

Uncaught TypeError: Cannot read properties of undefined (reading 'forEach') at bundle.js:45:442507 at bundle.js:45:442561 at t._onDataLoaded (bundle.js:45:442608) at FileReader.i.onload (bundle.js:45:443870)

[YubaC]

I also encountered this problem.
However, demo web page works well when I drop a mca file from version 1.7.10.
It's said that MOJANG changed the storage format after 1.18.
I don't know if this is the root of the problem.
Hope this will help you.