Cannot register custom file extension for JSON5 formatting

[EtiTheSpirit]

Cannot register custom file extension for JSON5 formatting

[molsonkiko]

You can achieve your goal as follows:

1. Open %AppData%/Roaming/Notepad++/langs.xml in any text editor.
2. Search for language name="json in the document. You should find an XML element that looks like this:

<Language name="json" ext="json" commentLine="" commentStart="" commentEnd="">
    <Keywords name="instre1">false null true</Keywords>
    <Keywords name="instre2">@id @context @type @value @language @container @list @set @reverse @index @base @vocab @graph</Keywords>
</Language>

3. Delete the value inside the ext attribute of the Language tag, so that the opening tag now looks like <Language name="json" ext="" commentLine="" commentStart="" commentEnd="">. This will make it so that the normal JSON lexer is no longer associated with the json file extension.
4. If a Language name="json5" element is already below the Language name="json" element, delete the json5 element.
5. Paste in the following between the Language name="json" element and whatever element came after it:

<Language name="json5" ext="json5 jsonc json" commentLine="//" commentStart="/*" commentEnd="*/">
    <Keywords name="instre1">false null true</Keywords>
    <Keywords name="instre2">@id @context @type @value @language @container @list @set @reverse @index @base @vocab @graph</Keywords>
</Language>

This will cause the json5 lexer to be associated with json5, json, and jsonc file extensions.
6. Reopen Notepad++, and the changes will be applied. Note that this will not apply automatically to any files that you already had open, so you will need to manually change any files you already had open. Notepad++ remembers the lexer it was using for a previously open file, and applies that instead of the default lexer for its extension.

[EtiTheSpirit]

I guess this method does work. It will have to do as a workaround for now, thank you!

That aside - unless someone else deems it better to do so, I think I will leave this open since this post was originally made wrt the Style Configurator not having the option, but this is definitely a good solution as-is.