I think I probably closed a snapcraft cli without exiting first on my ubuntu 18.04 computer. After that it would only restart with me in some wierd snap environment. After screwing around with grub I got the computer restarting properly and I uninstalled all snap apps and snap.
Then I installed snap and firefox. When I try to run firefox I get this error.
cannot locate the core or legacy core snap (current symlink missing?): No such file or directory