I've created new project in symfony and I get an error prompt on each site:
An error occurred while loading the web debug toolbar (404: Not Found).
Do you want to open the profiler?
When I open the profiler there is a message
Token not found
Token "59942c" was not found in the database.
Moreover, in the cache directory the profiler directory is empty! I checked permissions and they're proper. I tried cache:clear and removing cache manually, but that didn't help.
Answer
It's often problem with event subscriber/listener. Try run
console debug:event
And check for errors