https://apps.odoo.com/apps/themes/14.0/code_backend_theme/

When i installed a theme, Code Backend Theme, which indeed really cool theme to test and try out, in Community Version 14 ,

after enabling debug mode and updated, the theme is ok in the list . When i click install the theme , i got the error as following:

RPC_ERROR
Odoo Server Error

And

Traceback (most recent call last):
File "/odoo/odoo-server/odoo/tools/cache.py", line 85, in lookup
r = d[key]
File "/odoo/odoo-server/odoo/tools/func.py", line 71, in wrapper
return func(self, *args, **kwargs)
File "/odoo/odoo-server/odoo/tools/lru.py", line 34, in __getitem__
a = self.d[obj]
KeyError: ('ir.model.data', , 'web.assets_backend')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/odoo/odoo-server/odoo/tools/convert.py", line 680, in _tag_root
f(rec)
File "/odoo/odoo-server/odoo/tools/convert.py", line 658, in _tag_template
return self._tag_record(record)
File "/odoo/odoo-server/odoo/tools/convert.py", line 567, in _tag_record
f_val = self.id_get(f_ref)
File "/odoo/odoo-server/odoo/tools/convert.py", line 663, in id_get
res = self.model_id_get(id_str, raise_if_not_found)
File "/odoo/odoo-server/odoo/tools/convert.py", line 669, in model_id_get
return self.env['ir.model.data'].xmlid_to_res_model_res_id(id_str, raise_if_not_found=raise_if_not_found)
File "/odoo/odoo-server/odoo/addons/base/models/ir_model.py", line 1930, in xmlid_to_res_model_res_id
return self.xmlid_lookup(xmlid)[1:3]
File "", line 2, in xmlid_lookup
File "/odoo/odoo-server/odoo/tools/cache.py", line 90, in lookup
value = d[key] = self.method(*args, **kwargs)
File "/odoo/odoo-server/odoo/addons/base/models/ir_model.py", line 1923, in xmlid_lookup
raise ValueError('External ID not found in the system: %s' % xmlid)
ValueError: External ID not found in the system: web.assets_backend

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/odoo/odoo-server/odoo/addons/base/models/ir_http.py", line 238, in _dispatch
result = request.dispatch()
File "/odoo/odoo-server/odoo/http.py", line 688, in dispatch
result = self._call_function(**self.params)
File "/odoo/odoo-server/odoo/http.py", line 360, in _call_function
return checked_call(self.db, *args, **kwargs)
File "/odoo/odoo-server/odoo/service/model.py", line 94, in wrapper
return f(dbname, *args, **kwargs)
File "/odoo/odoo-server/odoo/http.py", line 348, in checked_call
result = self.endpoint(*a, **kw)
File "/odoo/odoo-server/odoo/http.py", line 917, in __call__
return self.method(*args, **kw)
File "/odoo/odoo-server/odoo/http.py", line 536, in response_wrap
response = f(*args, **kw)
File "/odoo/odoo-server/addons/web/controllers/main.py", line 1332, in call_button
action = self._call_kw(model, method, args, kwargs)
File "/odoo/odoo-server/addons/web/controllers/main.py", line 1320, in _call_kw
return call_kw(request.env[model], method, args, kwargs)
File "/odoo/odoo-server/odoo/api.py", line 461, in call_kw
result = _call_kw_multi(method, model, args, kwargs)
File "/odoo/odoo-server/odoo/api.py", line 448, in _call_kw_multi
result = method(recs, *args, **kwargs)
File "", line 2, in button_immediate_install
File "/odoo/odoo-server/odoo/addons/base/models/ir_module.py", line 74, in check_and_log
return method(self, *args, **kwargs)
File "/odoo/odoo-server/odoo/addons/base/models/ir_module.py", line 483, in button_immediate_install
return self._button_immediate_function(type(self).button_install)
File "/odoo/odoo-server/odoo/addons/base/models/ir_module.py", line 601, in _button_immediate_function
modules.registry.Registry.new(self._cr.dbname, update_module=True)
File "/odoo/odoo-server/odoo/modules/registry.py", line 88, in new
odoo.modules.load_modules(registry._db, force_demo, status, update_module)
File "/odoo/odoo-server/odoo/modules/loading.py", line 469, in load_modules
processed_modules += load_marked_modules(cr, graph,
File "/odoo/odoo-server/odoo/modules/loading.py", line 362, in load_marked_modules
loaded, processed = load_module_graph(
File "/odoo/odoo-server/odoo/modules/loading.py", line 221, in load_module_graph
load_data(cr, idref, mode, kind='data', package=package)
File "/odoo/odoo-server/odoo/modules/loading.py", line 69, in load_data
tools.convert_file(cr, package.name, filename, idref, mode, noupdate, kind)
File "/odoo/odoo-server/odoo/tools/convert.py", line 745, in convert_file
convert_xml_import(cr, module, fp, idref, mode, noupdate)
File "/odoo/odoo-server/odoo/tools/convert.py", line 811, in convert_xml_import
obj.parse(doc.getroot())
File "/odoo/odoo-server/odoo/tools/convert.py", line 731, in parse
self._tag_root(de)
File "/odoo/odoo-server/odoo/tools/convert.py", line 680, in _tag_root
f(rec)
File "/odoo/odoo-server/odoo/tools/convert.py", line 693, in _tag_root
raise ParseError('while parsing %s:%s, somewhere inside\n%s' % (
Exception

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/odoo/odoo-server/odoo/http.py", line 644, in _handle_exception
return super(JsonRequest, self)._handle_exception(exception)
File "/odoo/odoo-server/odoo/http.py", line 316, in _handle_exception
raise exception.with_traceback(None) from new_cause
odoo.tools.convert.ParseError: while parsing None:3, somewhere inside

Any idea? Thanks

Link: https://apps.odoo.com/apps/themes/14.0/code_backend_theme/