I have been trying to download some ISO from Win ISO Downloader, but I am getting this error

Please see this link for the actual error.   Win ISO Downloader Error Image [Screenshot]

I have tried on different machines, it works fine with no issues, but after some time, it starts showing problems after a while and never allows me to download any other ISO.

 

Any help will be helpful.

 

I am using 

Windows 10 x64 (ver. 20H2)