Mr. Mooneer, this is JH0PCF Kanda.
Regarding this matter
With a consultation from a friend of mine
I am posting.
I also use the same radio as my friend
It is possible to reproduce a certain environment in question.
The radio uses FTDX3000 from Yaesu.
The connection between the Windows PC and the radio is a USB connection,
Set the COM port on the CAT side to Flrig and FreeDV.
Specify PTT Config> Use Hamlib PTT
Rig Model is called Flrig Flrig.
In addition, WSJT -X and logging software are also related to Flrig.
Launch Flrig and set FreeDV's PTT Config as Flrig Flrig
When you start FreeDV, "Couldn't Conect to Radio With hamlib"
Error message is displayed and FreeDV software stops.
Is there any solution?