[MC-254382] Scoreboard not allowing creation of displayname

/scoreboard objectives add Countdown dummy

After typing out this command, Minecraft returns this error when I try to type a display name:

Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $

Comments 2

The display name needs to be valid json, not just text.
IE

{"text": "Some text ", "extra": [{"text": "with bold red behind it", "bold": true, "color": "red"}]}

If you're specifying a string, you need to enclose it in speech marks.