However... I just tried and I got another problem.
I tryed to make the USB live again, from the .iso of Solus 3 mate and while thinking about switching to "DD image" as you suggested.
- - With the 1st USB key (of 64 Go, in 3.0), when I enter in the "boot menu", it is finally suggested to launch Solus 3 Mate. So I choose that, then, a black screen appears, text is scrolling. Everything seems to go fine, and then, I find 2 Solus desktop, side by side, cloned, with no mouse cursor. Worried about it, I have to admit, I didn't try to install Solus. Plus, I remembered I made the USB live with Rufus on a computer with 2 screens, so, I thought that it could be the origin of the problem. So...
- - ... I took another USB key (of 8 Go, in 2.0), copy-pasted the iso of Solus and Rufus in it, and then, made again everything directly on my new laptop with a single screen, on windows 10. Then I restarted the computer, enter the boot menu, launch Solus 3 and... it only got worse. I still got the double screen, I think from the format I got of my screen, but it was all... confused. I couldn't understand anything which was happening on the screen. It was all scrambled. So, I had to shut down my computer.
Can someone help me again, please?
And at worst, is my problem the kind of issue I can fix by buying a DVD reader which can be plugged in USB port and by making a classic and good DVD iso? Making a USB live is really a pain it seems! ><
PS: Plus, I noticed that, by using this "DD image" option, all my USB keys got a decrease of capacity and I was unable to format them on my Windows 10. I hope that I'll find a way to get my keys back once I managed to install Solus, because a USB key of 64 Go is not very cheap... =/