I have a build, where I managed to throw in an excess of assets beyond the level limits. Twice now, when I've tried to change the build, by digging deeper and removing/adding some assets, it's been all crazy after having cancelled effect of the changes made, with long terramorphed pillars reaching far into the sky, and deep manholes reaching -21'ish deep that even affected neighbouring plots. Luckily though, everything has been fine after re-login.