Letsencrypt not working!

Hi all,

So I have the following configuration: Laravel Forge with a Vultr VPS running Ubuntu 18.04

I have a subdomain pointing to the ip adress of the VPS, when I try to install a letsencrypt ssl certificate I get the following error:

--2018-08-27 08:41:12--  https://forge-certificates.laravel.com/le/401447/603322?env=production
Resolving forge-certificates.laravel.com (forge-certificates.laravel.com)... 104.25.8.32, 104.25.9.32, 2400:cb00:2048:1::6819:820, ...
Connecting to forge-certificates.laravel.com (forge-certificates.laravel.com)|104.25.8.32|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [text/html]
Saving to: ‘letsencrypt_script1535359272’

     0K ..                                                     24.1M=0s

2018-08-27 08:41:12 (24.1 MB/s) - ‘letsencrypt_script1535359272’ saved [2579]

debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (This frontend requires a controlling tty.)
debconf: falling back to frontend: Teletype
dpkg-preconfigure: unable to re-open stdin: 
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-nIDFVi/pycparser/

I googled it but couldn't find any solution to this problem? Has someone an idea or did someone encountered the samen problem, and if so how did you fixed it?