Then turn the firewall on again by all means, before it becomes a safety hazard.
So Canon said 'your IP address has something wrong with it'... that frankly sounds rather ignorant and general. Let's examine the IP address of your computer briefly nonetheless, this way:
open a Command Prompt window
type this command into it:
and press the RETURN key, once.
It should display three things we need to examine:
1. Default Gateway - an IP Address of 4 numbers with . (periods) between them.
2. IP Address - formed the same way.
3. Subnet Mask - a simpler IP Address, almost certain to be 255.255.255.0
Let me know what those three values are, please.