Hello,
I tried to make new site (site3.dev), and install-app erpnext, then came error like below. Previously, I’ve tried to install erpnext on site2.dev with same issue like below:
The system is Ubuntu 18.04 64 bit, running on VirtualBox. ERPNext version 11 (staging).
Please help!
Thank you 
bench@osboxes:~/erpnext$ bench new-site site3.dev
MySQL root password:
Installing frappe...
Updating DocTypes for frappe : [========================================]
Updating country info : [========================================]
Set Administrator password:
Re-enter Administrator password:
*** Scheduler is disabled ***
bench@osboxes:~/erpnext$ bench use site3.dev
bench@osboxes:~/erpnext$ bench --site site3.dev install-app erpnext
Installing erpnext...
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 "/opt/bench/erpnext/apps/frappe/frappe/utils/bench_helper.py", line 97, in <module>
main()
File "/opt/bench/erpnext/apps/frappe/frappe/utils/bench_helper.py", line 18, in main
click.Group(commands=commands)(prog_name='bench')
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/click/core.py", line 764, in __call__
return self.main(*args, **kwargs)
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/click/core.py", line 717, in main
rv = self.invoke(ctx)
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/click/core.py", line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/click/core.py", line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/click/core.py", line 956, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/click/core.py", line 555, in invoke
return callback(*args, **kwargs)
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/click/decorators.py", line 17, in new_func
return f(get_current_context(), *args, **kwargs)
File "/opt/bench/erpnext/apps/frappe/frappe/commands/__init__.py", line 25, in _func
ret = f(frappe._dict(ctx.obj), *args, **kwargs)
File "/opt/bench/erpnext/apps/frappe/frappe/commands/site.py", line 165, in install_app
_install_app(app, verbose=context.verbose)
File "/opt/bench/erpnext/apps/frappe/frappe/installer.py", line 145, in install_app
sync_for(name, force=True, sync_everything=True, verbose=verbose, reset_permissions=True)
File "/opt/bench/erpnext/apps/frappe/frappe/model/sync.py", line 56, in sync_for
reset_permissions=reset_permissions, for_sync=True)
File "/opt/bench/erpnext/apps/frappe/frappe/modules/import_file.py", line 65, in import_file_by_path
ignore_version=ignore_version, reset_permissions=reset_permissions)
File "/opt/bench/erpnext/apps/frappe/frappe/modules/import_file.py", line 132, in import_doc
doc.insert()
File "/opt/bench/erpnext/apps/frappe/frappe/model/document.py", line 249, in insert
self.run_post_save_methods()
File "/opt/bench/erpnext/apps/frappe/frappe/model/document.py", line 905, in run_post_save_methods
self.run_method("on_update")
File "/opt/bench/erpnext/apps/frappe/frappe/model/document.py", line 772, in run_method
out = Document.hook(fn)(self, *args, **kwargs)
File "/opt/bench/erpnext/apps/frappe/frappe/model/document.py", line 1048, in composer
return composed(self, method, *args, **kwargs)
File "/opt/bench/erpnext/apps/frappe/frappe/model/document.py", line 1031, in runner
add_to_return_value(self, fn(self, *args, **kwargs))
File "/opt/bench/erpnext/apps/frappe/frappe/model/document.py", line 766, in <lambda>
fn = lambda self, *args, **kwargs: getattr(self, method)(*args, **kwargs)
File "/opt/bench/erpnext/apps/frappe/frappe/core/doctype/doctype/doctype.py", line 264, in on_update
self.run_module_method("on_doctype_update")
File "/opt/bench/erpnext/apps/frappe/frappe/core/doctype/doctype/doctype.py", line 331, in run_module_method
getattr(module, method)()
File "/opt/bench/erpnext/apps/erpnext/erpnext/stock/doctype/stock_ledger_entry/stock_ledger_entry.py", line 127, in on_doctype_update
if not frappe.db.has_index('tabStock Ledger Entry', 'posting_sort_index'):
File "/opt/bench/erpnext/env/local/lib/python2.7/site-packages/werkzeug/local.py", line 347, in __getattr__
return getattr(self._get_current_object(), name)
AttributeError: Database instance has no attribute 'has_index'