❔ error when converting string to long

System.FormatException: Input string was not in a correct format.

System.FormatException: Input string was not in a correct format.

you can see on image from what im trying to convert

public string ChangePercent24Hr { get; set; }
public long ChangePercent24HrD => long.Parse(ChangePercent24Hr);

public string ChangePercent24Hr { get; set; }
public long ChangePercent24HrD => long.Parse(ChangePercent24Hr);

❔ error when converting string to long - C#