Trisquel 10 update-manager

Hello, I'm using Trisquel 10 but for some reason the update-manager tool is not working correctly. When I run it from the terminal I get the following traceback:

```
Traceback (most recent call last):
File "/usr/bin/update-manager", line 118, in
app.start_update()
File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 220, in start_update
if apt_pkg.config.find_i("APT::Periodic::Update-Package-Lists") == 0:
NameError: name 'apt_pkg' is not defined
Error in sys.excepthook:
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 153, in apport_excepthook
with os.fdopen(os.open(pr_filename,
FileNotFoundError: [Errno 2] No such file or directory: '/var/crash/_usr_bin_update-manager.0.crash'

Original exception was:
Traceback (most recent call last):
File "/usr/bin/update-manager", line 118, in
app.start_update()
File "/usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py", line 220, in start_update
if apt_pkg.config.find_i("APT::Periodic::Update-Package-Lists") == 0:
NameError: name 'apt_pkg' is not defined
```