I'm running 18.04 with kernel 4.15.0-36-generic on a Lenovo thinkpad carbon x1 4th generation and I've been having some very persistent and annoying crashes. They occur pretty reliably when I suspend the laptop, but occasionally even when I haven't.
They start with either the wifi going out or elements of the UI disappearing. The terminal also responds to all commands with "command not found." Gradually all of the UI elements disappear, then the GUI disappears entirely to be replaced by what appears to be a log file of some kind continually updating.
Any ideas? I haven't been able to find anyone out there that was having precisely the same problem as I have. This thread seemed close, but I'm already on a version of the kernel where the problem is supposedly fixed. In the interests of full disclosure, I'm dual booting with Windows 10 and I initially updated to 18.04 from (IIRC) 16.10 to fix a similar problem but its only gotten worse. I just did a fresh install of both OS's and the problem persisted.
Thanks!