I have at least spotify and docker installed via snap. Both of these fail with the same error message:
"cannot perform readlinkat() on the mount namespace file descriptor of the init process: Permission denied".
Some other snap apps work for me.
I am using 18.04 and have applied all updates. Neither rebooting nor reinstalling fix the issue. And nor does reinstalling snap itself.
I am unsure as to how to go about fixing the issue.