Hi!
I have a acer a715-71g notebook.
Leap: Sorry, the installer does not start! It starts but it only reaches “loading basic drivers”, Then the picture freezes and does not react.
tumbleweed: Your installer starts without problem.
Thank you help me. 
Please see the release notes here: https://doc.opensuse.org/release-notes/x86_64/openSUSE/Leap/15.0/#sec.driver
Try booting with the nouveau.modeset=0 option.
At the boot screen press “E” for “edit”, look for a line beginning with “linuxefi” and append “nouveau.modeset=0 option” (without quotes).
If possible do an install with network and external repositories enabled, so that you install the last version of the kernel that should have fixed this problem.
If the TW installer boots fine (with a much newer kernel…) there is a good chance that your problem is indeed the broken nouveau driver.