Description of problem:
I test F26 rawhide, and yumex-dnf don't work and show me this error:

g-io-error-quark: GDBus.Error:org.freedesktop.DBus.Python.AttributeError: Traceback (most recent call last):
  File "/usr/lib64/python3.5/site-packages/dbus/service.py", line 707, in _message_cb
    retval = candidate_method(self, *args, **keywords)
  File "/usr/lib/python3.5/site-packages/dnfdaemon/server/__init__.py", line 83, in newFunc
    rc = func(*args, **kwargs)
  File "/usr/share/dnfdaemon/dnfdaemon-system", line 207, in SetConfig
    rc = self.set_option(setting, value)
  File "/usr/lib/python3.5/site-packages/dnfdaemon/server/__init__.py", line 680, in set_option
    if hasattr(self.base.conf, option):
  File "/usr/lib/python3.5/site-packages/dnfdaemon/server/__init__.py", line 202, in base
    self._get_base()
  File "/usr/lib/python3.5/site-packages/dnfdaemon/server/__init__.py", line 1054, in _get_base
    self._base.setup_base()
  File "/usr/lib/python3.5/site-packages/dnfdaemon/server/backend.py", line 71, in setup_base
    self._packages = Packages(self)
  File "/usr/lib/python3.5/site-packages/dnfdaemon/server/backend.py", line 273, in __init__
    self._inst_na = self._sack.query().installed().na_dict()
AttributeError: 'Query' object has no attribute 'na_dict'
 (36)

In console, dnf upgrade work fine.