[SOLVED]: Outbound emails not working - Worker Error

I am on version 7.0.18. Outbound emails on my erpnext system are not working when i checked in detail i found that the worker short and long processes were not starting and giving error as under:

`File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 991, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 837, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 464, in invoke
return callback(*args, **kwargs)
File “/home/arj/frappe-bench/apps/frappe/frappe/commands/scheduler.py”, line 163, in start_worker
start_worker(queue)
File “/home/arj/frappe-bench/apps/frappe/frappe/utils/background_jobs.py”, line 102, in start_worker
Worker(queues, name=get_worker_name(queue)).work()
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/rq/worker.py”, line 135, in init
self.validate_queues()
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/rq/worker.py”, line 179, in validate_queues
raise TypeError(’{0} is not of type {1} or text type’.format(queue, self.queue_class))
TypeError: default is not of type <class ‘rq.queue.Queue’> or text type
Traceback (most recent call last):
File “/usr/lib/python2.7/runpy.py”, line 162, in _run_module_as_main
main”, fname, loader, pkg_name)
File “/usr/lib/python2.7/runpy.py”, line 72, in _run_code
exec code in run_globals
File “/home/arj/frappe-bench/apps/frappe/frappe/utils/bench_helper.py”, line 79, in
main()
File “/home/arj/frappe-bench/apps/frappe/frappe/utils/bench_helper.py”, line 16, in main
click.Group(commands=commands)(prog_name=‘bench’)
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 664, in call
return self.main(*args, **kwargs)
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 644, in main
rv = self.invoke(ctx)
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 991, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 991, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 837, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py”, line 464, in invoke
return callback(*args, **kwargs)
File “/home/arj/frappe-bench/apps/frappe/frappe/commands/scheduler.py”, line 163, in start_worker
start_worker(queue)
File “/home/arj/frappe-bench/apps/frappe/frappe/utils/background_jobs.py”, line 102, in start_worker
Worker(queues, name=get_worker_name(queue)).work()
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/rq/worker.py”, line 135, in init
self.validate_queues()
File “/home/arj/frappe-bench/env/local/lib/python2.7/site-packages/rq/worker.py”, line 179, in validate_queues
raise TypeError(’{0} is not of type {1} or text type’.format(queue, self.queue_class))
TypeError: short is not of type <class ‘rq.queue.Queue’> or text type
"

I have tried:
pip install --upgrade -r requirements.txt
after installation the error remains same, Please indicate corrective action.
Thanks

Got it correct. Correct command that has to be run in frappe-bench folder is:
./env/bin/pip install --upgrade -r requirements.txt

Now workers are running fine and outbound emails working.