There is no formatter for 'routeros' files installed.

[tysonclugg]

It would be helpful if this extension could help us format our RouterOS scripts. I tried formatting a script using this extension, but an error with the subject of this issue was shown instead of my script being formatted.

https://code.visualstudio.com/blogs/2016/11/15/formatters-best-practices

To summarize, an extension that implements the formatting extension API properly will do the following:

1. Register formatters via registerDocumentFormattingEditProvider.
2. Implement the formatting logic per the DocumentFormattingEditProvider interface.
3. Have a setting to enable / disable the formatter.
4. Add the "Formatters" category to the extension manifest.