How do I fix error CS7036 there is no argument given that corresponds to the required formal parameter 'cat' of 'record.record(string, string) in unity C#

I'm going to assume your FixRecord class inherits from a class that looks like

public class SomeBaseClass
{
    public SomeBaseClass(string cat, string msg)
    {

    }
}

If you create a class that inherits a class then you have to pass the relevant parameters to that base class's constructor (the two string variables). Your FixRecord has two constructors, one with multiple params and one with none. The one with multiple params calls the base class constructor properly (the ": base" code), but the one with no params doesn't.

How you fix this "depends". If you never want to create your class with no params;

var x = new FixRecord();

then simply remove the constructor that is causing the issue. If you do want to create your class with no params then you have to decide what default values are given to the base class constructor. So if this is to be an empty string then update the constructor like

public FixRecord() : base (string.Empty, string.Empty)
{

}