我只是一步一步地按照教程学习，即使这样，我也会遇到错误。在“扩展默认标题”一章中-> https://www.odoo.com/documentation/12.0/howtos/themes.html#extend-the-default-header
在“网站/配置/应用程序”中，安装主题，然后在“网站/配置/设置”中，单击“选择主题”按钮，然后在其中选择要使用的主题。
但是，此时会出现如下错误消息：
Error:
Odoo Server Error
Traceback (most recent call last):
File "/odoo/odoo-server/odoo/tools/convert.py", line 757, in parse
self._tags[rec.tag](rec, de, mode=mode)
File "/odoo/odoo-server/odoo/tools/convert.py", line 735, in _tag_template
return self._tag_record(record, data_node)
File "/odoo/odoo-server/odoo/tools/convert.py", line 573, in _tag_record
model = self.env[rec_model]
File "/odoo/odoo-server/odoo/api.py", line 820, in __getitem__
return self.registry[model_name]._browse((), self)
File "/odoo/odoo-server/odoo/modules/registry.py", line 176, in __getitem__
return self.models[model_name]
KeyError: 'theme.ir.ui.view'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/odoo/odoo-server/odoo/http.py", line 653, in _handle_exception
return …