Both, your map and your OS is about 1-1/2 year old.
When you connect to PC is MyDrive Connect opening up and displays which model TomTom is connected?
When it opens up it should ask you to enter your user name and password, if it only shows dots for the password delete those and enter your password again.
Be sure that both are the
SAME on MyDrive Connect as on your Trucker 6000.
What type of PC are you using to connect?
You may also want to download a fresh version of MDC at
https://www.tomtom.com/en_gb/mydrive-connect/
and just install it (no need to remove the existing one).