Error:Seahub failed to start : LC_ALL is not set in ENV, set to en_US.UTF-8

I am facing issue in seahub start.
and it is showing below mentioned message

./seahub.sh start
LC_ALL is not set in ENV, set to en_US.UTF-8
Starting seahub at port 8000 …
Error:Seahub failed to start.
Please try to run “./seahub.sh start” again

so I have tried ./seahub.sh start-fastcgi

LC_ALL is not set in ENV, set to en_US.UTF-8
Starting seahub (fastcgi) at 127.0.0.1:8000 …
Traceback (most recent call last):
File “/home/ayush/projects/kaka/seafile-server-7.1.4/seahub/manage.py”, line 10, in
execute_from_command_line(sys.argv)
File “/home/ayush/projects/kaka/seafile-server-7.1.4/seahub/thirdpart/django/core/management/init.py”, line 364, in execute_from_command_line
utility.execute()
File “/home/ayush/projects/kaka/seafile-server-7.1.4/seahub/thirdpart/django/core/management/init.py”, line 338, in execute
django.setup()
File “/home/ayush/projects/kaka/seafile-server-7.1.4/seahub/thirdpart/django/init.py”, line 27, in setup
apps.populate(settings.INSTALLED_APPS)
File “/home/ayush/projects/kaka/seafile-server-7.1.4/seahub/thirdpart/django/apps/registry.py”, line 85, in populate
app_config = AppConfig.create(entry)
File “/home/ayush/projects/kaka/seafile-server-7.1.4/seahub/thirdpart/django/apps/config.py”, line 94, in create
module = import_module(entry)
File “/usr/lib/python3.5/importlib/init.py”, line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File “”, line 986, in _gcd_import
File “”, line 969, in _find_and_load
File “”, line 956, in _find_and_load_unlocked
ImportError: No module named ‘captcha’
Error:Seahub failed to start.

Kindly help me it’s quite urgent , and I want to know that how the synchronization works in seafile between different devices over different platforms like Android, MAC, Windows and Linux

You need at least python 3.6 and certain modules. Please use the search function for more details. The error you are experiencing was discussed multiple times already.

I have tried to find and even 2-3 similar cases but not exactly same .

Exactly the same: Error:Seahub failed to start. Try again

Still, this will not solve your python version problem.