Then you have to append nomodeset or eventually nouveau.modeset=0 to the kernel parameters of the live ISO.
just spam the space bar when the computer starts to show the boot menu then press e to add the extra parameters.
nomodeset may be enough, the other one is for nvidia cards
radeon.modeset=0 or both
Found this at: https://discuss.getsol.us/d/1019-black-screen-after-usb-boot-but-sound-works/4
Maybe it is the other way around, looking at your error, that you have to remove
nomodeset parameters from the commandline... from the USB stick with Solus .iso,
I did take a look at the .iso , but there is no
nomodeset kernel commandline there, so try to add those 2 mentioned above?
just spam the space bar when the computer starts to show the boot menu then press e to add the extra parameters