Error handling for missing JSON files

[fr0gger03]

Describe the bug

If the config.ini is set to import a section, but the corresponding JSON file is missing from the directory, would like to gracefully handle the error and provide informative help message.

Reproduction steps

1. configure import setting in config.ini to TRUE
2. delete / remove associated JSON file
3. attempt import
   ...

Expected behavior

gracefully handle the error and provide informative help message.

Additional context

No response