Installation issue

Hey... I am facing some issue while installing Kali Linux 2019.4 ....can any one can fix it??
The issue is:
"your installation media couldn't be mounted. When installing from CD rom , this probably means that the disk was not in the drive if so
You can insert it and try again"
By clicking try again the same massage appears...
Note: I am installing it from bootable USB.
Help plz.............

You just take out the USB for 3 to 4 seconds and insert it again. Then you can retry. Hopefully it will help you.