sudo su

nano /etc/ca-certificates.conf

find the line where it says: mozilla/QuoVadis_Root_CA_2_G3.crt change it to say: 

!mozilla/QuoVadis_Root_CA_2_G3.crt

then save and exit (ctrl+X then Y)


update-ca-certificates --fresh


mv /usr/local/share/ca-certificates/QuoVadisRootCA2G3.crt /root

mv /usr/local/share/ca-certificates/QuoVadisGlobalSSLICA-G3.crt /tmp 

update-ca-certificates --fresh

nano QuoVadisRootCA2G3.crt

then download this and, open in notepad and paste contents into nano
https://www.quovadisglobal.com/wp-content/files/media/qvrca2g3_pem.pem 
then save and exit (ctrl+X then Y)

nano QuoVadisGlobalSSLICA-G3.crt

then download this and, open in notepad and paste contents into nano
https://www.quovadisglobal.com/wp-content/files/media/quoVadisglobalsslicag3-pem.pem

then save and exit (ctrl+X then Y)

update-ca-certificates

then you need to run restarts of these services for the changes to finalise

service ussgw_sysmond restart

wait at least 20 seconds

systemctl stop uss-squid5
systemctl start uss-squid5