I have a node that I have just moved from puppet 3 to 4 and am getting this error on... any ideas how to debug this?

Debug: Prefetching pip resources for package
Debug: Executing '/usr/bin/pip freeze'
Debug: Storing state
Info: Creating state file /opt/puppetlabs/puppet/cache/state/state.yaml
Debug: Stored state in 0.23 seconds

Error: Failed to apply catalog: [nil]This machine has LOTS of resources (probably too many) and that is something we are working on, but it ran on 3 at least. I already tried whacking the state dir and the cache dir.