Lubuntu Next is still under heavy development, and as such you should expect things to be a little rough around the edges. If you find a bug, report it below, or feel free to go to #lubuntu-devel on freenode and ask around there.
Since ISO Testing can touch many different packages, it's important to make an effort to file your bug against the appropiate package so it can be seen by those who can help. See Reporting Bugs.
Not sure which package to file against? See Finding the right package and the chart below for help.
For problems encountered ...
... during the installation itself: ubuntu-bug ubiquity
... while booting the ISO image: ubuntu-bug syslinux
... while booting the system after installation: ubuntu-bug grub2
... with the graphical display after installation: ubuntu-bug xorg
... with an application: ubuntu-bug PACKAGE_NAME
