I get error after update 
Migrating mysite
Updating DocTypes for frappe : [========================================]
Updating DocTypes for erpnext : [============= ]Traceback (most recent call last):
File "/usr/lib/python2.7/runpy.py", line 174, 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/mohd/frappe-bench/apps/frappe/frappe/utils/bench_helper.py", line 97, in <module>
main()
File "/home/mohd/frappe-bench/apps/frappe/frappe/utils/bench_helper.py", line 18, in main
click.Group(commands=commands)(prog_name='bench')
File "/home/mohd/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 722, in __call__
return self.main(*args, **kwargs)
File "/home/mohd/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 697, in main
rv = self.invoke(ctx)
File "/home/mohd/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/mohd/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/home/mohd/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/home/mohd/frappe-bench/env/local/lib/python2.7/site-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/home/mohd/frappe-bench/env/local/lib/python2.7/site-packages/click/decorators.py", line 17, in new_func
return f(get_current_context(), *args, **kwargs)
File "/home/mohd/frappe-bench/apps/frappe/frappe/commands/__init__.py", line 25, in _func
ret = f(frappe._dict(ctx.obj), *args, **kwargs)
File "/home/mohd/frappe-bench/apps/frappe/frappe/commands/site.py", line 222, in migrate
migrate(context.verbose, rebuild_website=rebuild_website)
File "/home/mohd/frappe-bench/apps/frappe/frappe/migrate.py", line 41, in migrate
frappe.model.sync.sync_all(verbose=verbose)
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/sync.py", line 19, in sync_all
sync_for(app, force, verbose=verbose, reset_permissions=reset_permissions)
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/sync.py", line 56, in sync_for
reset_permissions=reset_permissions, for_sync=True)
File "/home/mohd/frappe-bench/apps/frappe/frappe/modules/import_file.py", line 58, in import_file_by_path
ignore_version=ignore_version, reset_permissions=reset_permissions)
File "/home/mohd/frappe-bench/apps/frappe/frappe/modules/import_file.py", line 132, in import_doc
doc.insert()
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/document.py", line 249, in insert
self.run_post_save_methods()
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/document.py", line 898, in run_post_save_methods
self.run_method("on_update")
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/document.py", line 765, in run_method
out = Document.hook(fn)(self, *args, **kwargs)
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/document.py", line 1040, in composer
return composed(self, method, *args, **kwargs)
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/document.py", line 1023, in runner
add_to_return_value(self, fn(self, *args, **kwargs))
File "/home/mohd/frappe-bench/apps/frappe/frappe/model/document.py", line 759, in <lambda>
fn = lambda self, *args, **kwargs: getattr(self, method)(*args, **kwargs)
File "/home/mohd/frappe-bench/apps/frappe/frappe/core/doctype/doctype/doctype.py", line 244, in on_update
self.run_module_method("on_doctype_update")
File "/home/mohd/frappe-bench/apps/frappe/frappe/core/doctype/doctype/doctype.py", line 310, in run_module_method
module = load_doctype_module(self.name, self.module)
File "/home/mohd/frappe-bench/apps/frappe/frappe/modules/utils.py", line 187, in load_doctype_module
raise ImportError('Module import failed for {0} ({1})'.format(doctype, module_name + ' Error: ' + str(e)))
ImportError: Module import failed for Supplier Type (erpnext.setup.doctype.supplier_type.supplier_type Error: No module named supplier_type.supplier_type)