Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 272, in refresh_cache
    self.update_list.update(self.cache)
  File "/usr/lib/python3/dist-packages/UpdateManager/Core/UpdateList.py", line 84, in update
    self.distUpgradeWouldDelete = cache.saveDistUpgrade()
  File "/usr/lib/python3/dist-packages/UpdateManager/Core/MyCache.py", line 126, in saveDistUpgrade
    self._depcache.upgrade(True)
SystemError: E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/bin/update-manager", line 115, in <module>
    app.start_update()
  File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 160, in start_update
    self.start_available()
  File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 167, in start_available
    self.refresh_cache()
  File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 278, in refresh_cache
    "package and include the following error message:\n") + e
TypeError: Can't convert 'SystemError' object to str implicitly