Couldn't parse loot table, expected '{' at position 0.

To be fast, the Json file it's completely fine, I rewrite it, reloaded the world & still happens this error:

Couldn't parse loot table dungeon_travelers:mob/earth_warden/wild com.google.gson.JsonSyntaxException: Expected '{' at position 0: <--[HERE] 

What I expected to happen was:

The loot table worked & no Output log error.

What actually happened was:

The loot table didn't worked & there was an error:

Couldn't parse loot table example:example
com.google.gson.JsonSyntaxException: Expected '{' at position 0: <--[HERE]  

1. Launch Minecraft with the output log enabled.
2. Open the example world I attatched with a datapack.
3. Check t