odd - after logging into the launchpad account you should have been given the option to enter a comment on what the issue is. You should also receive an email with your bug report number.
You ubiquity bugs will appear here https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bugs?orderby=-id&start=0
(order by the number in descending order to see the latest first)
Thanks, I’ve just reported it manually on that page.
@Jason I had a similar problem, I think it was OK the first time, but happened when I used the CD/USB stick for a second time.
Chris, I just tried it again just now (Tuesday 6:30 PM, EST) with another failure.
I wiped the USB with the Disk Utility on my C2Duo 2010 macbook, and used Etcher to create a bootable drive with the daily build from April 10th. It got as far as another login screen, and I quit out of it.
I’ll try it again lter in the week, erase the USB again and format it to something else? EX FAT, perhaps?
Rats.
Chris, tried today again (Wednesday April 11th) on 2 separate USBs, formatted to: Mac OS Extended, then EX FAT, finally DOS FAT
None of them would get past the login/password screen. Kubuntu also briefly hung on a bootload screen but timed out past the login request and loaded the DE. When I did get past the login last weekend (April 7/8th), Ubuntu Budgie, Kubuntu and Ubuntu proper all lacked a wifi option at all. I’ll keep trying - Jason
sounds like you have got two specific issues here - one graphical (cannot get past login screen - so the window manager is crashing) … the second is wifi.
Now I don’t know what graphics you are using but I guess nvidia? Try booting with nomodeset in your grub https://askubuntu.com/questions/38780/how-do-i-set-nomodeset-after-ive-already-installed-ubuntu - if it works then look for a proprietary driver offered in software & Updates - drivers.
For wifi - cannot help here - I would suggest the experts on wifi issues hangout on ubuntuforums.org / askubuntu.com - but first you need to login reliably.
FF, Hello! I am trying to login! 
(Project looks great BTW, I’ve used the 17.10 build) Your answer suggests it’s me, not you
My GPU is nothing at all. I’m using the built-in directly on my mac motherboard, whatever Apple provides. It’s a shared intel, I think. I’ll follow your links and try to boot w nomodeset. I agree: login first, wifi second. Thanks FF, I’ll report back in the next few days – your April 25th deadline is imminent!
@Jason actually its the 26th … but really that is the “first” launch. Many users actually upgrade at 18.04.1 in late July - the more adventurous people find all the issues between the 26th April and July - hopefully then fixed … and then all is fairly quiet for the mass of people updating at 18.04.1.
Those late adopters – suckers! ha! I’m installing Ubuntu Budgie 18.04 Beta 02 right now alongside Ubuntu MATE 18.04, looks fine so far. I can see in the installer that my WIFI issue was because there’s no live wifi on the installer, it’s installed separately. No login issues this time – Why was I able to get past the login this time?
Jason again – Linux has famously invited everyone to the party, and I joyfully throw my oldest wacom tablets at it. I currently have this beta installed on a Dell Inspiron Core 2 Duo with 4 GB of ram. It’s a bit laggy, but fun to see working. Spotify installed nicely from the Software Centre
I inserted an EX FAT format USB, and it was rejected. What do I need to know about this? (ie, what have I done wrong?) OR: Is this something you are working on, or is this merely a symptom of being a beta?