dataiku start command not working

dss start
Traceback (most recent call last):
File "/usr/lib64/python2.7/runpy.py", line 174, in _run_module_as_main
"__main__", fname, loader, pkg_name)
File "/usr/lib64/python2.7/runpy.py", line 72, in _run_code
exec code in run_globals
File "/home/dataiku/dataiku-dss-9.0.7/python.packages/supervisor/supervisord.py", line 40, in <module>
from supervisor.options import ServerOptions
File "/home/dataiku/dataiku-dss-9.0.7/python.packages/supervisor/options.py", line 13, in <module>
import pkg_resources
File "/apps/dataiku-data/pyenv/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 36, in <module>
import email.parser
ImportError: No module named parser

Operating system used: AMI