Creating install USB-Stick- Validation Failed

Hi,

Ive got a problem creating the Installation Stick.

At the validating Process I get the Error Message:

Failed to validate installer, cannot continue.

(Take a look at the screenshot)

OCLP version: 2.0.2

Model: MacMini 6,2 updating from 10.15.07

Ive bought a new 32GB USB Stick....... is the Stick really the problem?

Does anyone know how I can fix this?

Thanxs