Issues upgrading from v.10 to v.11 Ubuntu 14.04 on VM (hyper-v)

I have been trying to upgrade an ERPnext v.10 for the past few weeks. When I trying to run bench switch-to-branch version-11 frappe erpnext --upgrade, I got the following errors:
" > Aborting

Error switching to branch version-11 for erpnext
Updating Python libraries…
INFO:bench.utils:./env/bin/pip install --upgrade pip
/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#snimissingwarning.
SNIMissingWarning
/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see Advanced Usage - urllib3 2.0.3 documentation.
InsecurePlatformWarning
Requirement already up-to-date: pip in ./env/lib/python2.7/site-packages
/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see Advanced Usage - urllib3 2.0.3 documentation.
InsecurePlatformWarning
INFO:bench.utils:./env/bin/pip install -q -r /home/frappe/.bench/requirements.txt
/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:318: SNIMissingWarning: An HTTPS request has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may cause the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer version of Python to solve this. For more information, see Advanced Usage - urllib3 2.0.3 documentation.
SNIMissingWarning
/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see Advanced Usage - urllib3 2.0.3 documentation.
InsecurePlatformWarning
Could not find a version that satisfies the requirement virtualenv (from -r /home/frappe/.bench/requirements.txt (line 3)) (from versions: )
No matching distribution found for virtualenv (from -r /home/frappe/.bench/requirements.txt (line 3))
/home/frappe/frappe-bench/env/local/lib/python2.7/site-packages/pip/vendor/requests/packages/urllib3/util/ssl.py:122: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade to a newer version of Python to solve this. For more information, see Advanced Usage - urllib3 2.0.3 documentation.
InsecurePlatformWarning
Traceback (most recent call last):
File “/usr/local/bin/bench”, line 11, in
load_entry_point(‘bench’, ‘console_scripts’, ‘bench’)()
File “/home/frappe/.bench/bench/cli.py”, line 40, in cli
bench_command()
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 722, in call
return self.main(*args, **kwargs)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 697, in main
rv = self.invoke(ctx)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 535, in invoke
return callback(*args, **kwargs)
File “/home/frappe/.bench/bench/commands/update.py”, line 122, in switch_to_branch
switch_to_branch(branch=branch, apps=list(apps), upgrade=upgrade)
File “/home/frappe/.bench/bench/app.py”, line 305, in switch_to_branch
switch_branch(branch, apps=apps, bench_path=bench_path, upgrade=upgrade)
File “/home/frappe/.bench/bench/app.py”, line 295, in switch_branch
update_requirements()
File “/home/frappe/.bench/bench/utils.py”, line 406, in update_requirements
install_requirements(pip, bench_req_file)
File “/home/frappe/.bench/bench/utils.py”, line 446, in install_requirements
exec_cmd(“{pip} install -q -r {req_file}”.format(pip=pip, req_file=req_file))
File “/home/frappe/.bench/bench/utils.py”, line 140, in exec_cmd
raise CommandFailedError(cmd)
bench.utils.CommandFailedError: ./env/bin/pip install -q -r /home/frappe/.bench/requirements.txt "

I have also tried to sudo chown - R frappe:frappe /home/frappe/.bench and /frappe-bench,
git reset --hard
git pull
cd /home/frappe/frappe-bench
bench switch-to-branch version-11 frappe erpnext --upgrade

and got the following errors:
" > npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@^1.0.0 (node_modules/chokidar/node_modules/fsevents):

npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {“os”:“darwin”,“arch”:“any”} (current: {“os”:“linux”,“arch”:“x64”})
npm WARN frappe@ No description
Traceback (most recent call last):
File “/usr/local/bin/bench”, line 11, in
load_entry_point(‘bench’, ‘console_scripts’, ‘bench’)()
File “/home/frappe/.bench/bench/cli.py”, line 41, in cli
bench_command()
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 722, in call
return self.main(*args, **kwargs)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 697, in main
rv = self.invoke(ctx)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 535, in invoke
return callback(*args, **kwargs)
File “/home/frappe/.bench/bench/commands/update.py”, line 43, in switch_to_branch
switch_to_branch(branch=branch, apps=list(apps), upgrade=upgrade)
File “/home/frappe/.bench/bench/app.py”, line 417, in switch_to_branch
switch_branch(branch, apps=apps, bench_path=bench_path, upgrade=upgrade)
File “/home/frappe/.bench/bench/app.py”, line 409, in switch_branch
reload_module(utils)
NameError: global name ‘utils’ is not defined "

There is no customization. Can someone give me some pointers? I have tried to search the forum and google and tried various things? Thanks in advance.