Example script: Item density per chunk (Anvil format compatible)
https://gist.github.com/fakuivan/33e681a4ae4892ff6dd3c77ae6eeda2e
Hello @fakuivan. Your script uses some tags that do not exist anymore in the chunck section, in the latest Anvil format used by today's 1.13.x game version (Blocks and Add tags were replaced by Palette and BlockStates, plus a variable bit length index).
The proposed script is now superseded by the 'block analysis' example as updated in #106, that now supports both McRegion and Anvil formats. You could close this issue.
@mfld-fr Thanks for your contribution! @fakuivan Please check, and if this indeed fixes your issue, please close the issue.