I can't install apps, please help me.

Error:

Odoo Server Error



Traceback (most recent call last):

  File "/odoo/odoo-server/odoo/http.py", line 646, in _handle_exception

    return super(JsonRequest, self)._handle_exception(exception)

  File "/odoo/odoo-server/odoo/http.py", line 307, in _handle_exception

    raise pycompat.reraise(type(exception), exception, sys.exc_info()[2])

  File "/odoo/odoo-server/odoo/tools/pycompat.py", line 87, in reraise

    raise value

  File "/odoo/odoo-server/odoo/http.py", line 683, in dispatch

    result = self._call_function(**self.params)

  File "/odoo/odoo-server/odoo/http.py", line 339, in _call_function

    return checked_call(self.db, *args, **kwargs)

  File "/odoo/odoo-server/odoo/service/model.py", line 97, in wrapper

    return f(dbname, *args, **kwargs)

  File "/odoo/odoo-server/odoo/http.py", line 332, in checked_call

    result = self.endpoint(*a, **kw)

  File "/odoo/odoo-server/odoo/http.py", line 927, in __call__

    return self.method(*args, **kw)

  File "/odoo/odoo-server/odoo/http.py", line 512, in response_wrap

    response = f(*args, **kw)

  File "/odoo/odoo-server/addons/web/controllers/main.py", line 924, in call_button

    action = self._call_kw(model, method, args, {})

  File "/odoo/odoo-server/addons/web/controllers/main.py", line 912, in _call_kw

    return call_kw(request.env[model], method, args, kwargs)

  File "/odoo/odoo-server/odoo/api.py", line 689, in call_kw

    return call_kw_multi(method, model, args, kwargs)

  File "/odoo/odoo-server/odoo/api.py", line 680, in call_kw_multi

    result = method(recs, *args, **kwargs)

  File "<decorator-gen-39>", line 2, in button_immediate_install

  File "/odoo/odoo-server/odoo/addons/base/module/module.py", line 71, in check_and_log

    return method(self, *args, **kwargs)

  File "/odoo/odoo-server/odoo/addons/base/module/module.py", line 438, in button_immediate_install

    return self._button_immediate_function(type(self).button_install)

  File "/odoo/odoo-server/odoo/addons/base/module/module.py", line 531, in _button_immediate_function

    modules.registry.Registry.new(self._cr.dbname, update_module=True)

  File "/odoo/odoo-server/odoo/modules/registry.py", line 84, in new

    odoo.modules.load_modules(registry._db, force_demo, status, update_module)

  File "/odoo/odoo-server/odoo/modules/loading.py", line 343, in load_modules

    loaded_modules, update_module)

  File "/odoo/odoo-server/odoo/modules/loading.py", line 242, in load_marked_modules

    loaded, processed = load_module_graph(cr, graph, progressdict, report=report, skip_modules=loaded_modules, perform_checks=perform_checks)

  File "/odoo/odoo-server/odoo/modules/loading.py", line 130, in load_module_graph

    model_names = registry.load(cr, package)

  File "/odoo/odoo-server/odoo/modules/registry.py", line 248, in load

    model = cls._build_model(self, cr)

  File "/odoo/odoo-server/odoo/models.py", line 426, in _build_model

    raise TypeError("Model %r does not exist in registry." % name)

TypeError: Model 'stock.pack.operation' does not exist in registry.