Did you enter 0 for number of teeth on the second gear?
You can enter 0 on 1st gear ('Gear to be drawn') then a number on 2nd gear ('Other gear').
The pitch radius of the gear will be the 'Distance between centers'.
You will still get an error 95 but you will get a gear.
Or you can enter the same number of teeth on both gears and enter the pitch diameter in 'Distance between centers'.
Then delete one of the gears.
You can enter 0 on 1st gear ('Gear to be drawn') then a number on 2nd gear ('Other gear').
The pitch radius of the gear will be the 'Distance between centers'.
You will still get an error 95 but you will get a gear.
Or you can enter the same number of teeth on both gears and enter the pitch diameter in 'Distance between centers'.
Then delete one of the gears.