i two time create custom live
But the first time
On all options, including text mode and graphics mode. I clicked invalid linux kernel or corrupted error occurred

But the second timee create custom live

On all options, including text mode and graphics mode. I clicked

After loading Ubuntu screen was black and was open terminal and I should think enter command . I did not install successfully,Why is displayed the terminal instead of install page?
Terminal shows the following text:

documantation https://help.ubuntu.com
to run command adminstrator(user"root"),use"sudo<command>
custom@custom:~$