Wrong client ID throws "Grant type refresh_token is not supported."

[Head]

I did a post to https://login.eveonline.com:443/v2/oauth/token with my old/invalid client ID and got the error: Grant type refresh_token is not supported. instead of something like "Invalid Client ID or Secret"
This was very misleading and took me forever to find my mistake.

[Inomares]

This also applies to sending as wrong content type ie query params instead of data.

[stebet]

This should be fixed in an upcoming release.