Watch_Dogs Online Multiplayer how to fix/access

Purchase the game again on Ubisoft Connect. Make sure you purchase the "Standard Edition." The "Complete Edition" recently ran out of online license on Ubisoft Connect. After purchasing it, install and play the game for 10 to 15 minutes. Then, play one round of multiplayer on Steam. If it works, congrats! You now have full access to online multiplayer on Steam. If not, play until you reach the multiplayer tutorial level. It should work after that. Once you confirm that it works, you can refund the game on Ubisoft Connect and access online multiplayer on Steam.

Contact Ubisoft Support and provide proof of purchase for the game. Show them that you completed the "2XTheTap" mission. Then, ask if they can provide you with a Multiplayer Key. They may ask you some questions about your network. Answer them until they determine that it's a license issue. After that, redeem the key they gave you on Ubisoft Connect. Follow the same process as in the first method. You will then have two copies of the game on Ubisoft Connect and Steam.

NexusTools has released custom online servers
you dont need the game on ubisoft to make online work there. it works on any version of the game
its still WIP but all gamemodes work
and for those that dont want to buy the game again on ubisoft connect or talk to ubi support you can use this to get the achievements you need.

links to get NexusTools:

https://discord.gg/48GF2kFd4q
https://www.nexusmods.com/watchdogs/mods/491

The answer is no. The Ubisoft Connect and Steam version use different save files, so you don't need to backup anything.

After using one of these methods, you should be able to access the hacker world on Watch_Dogs!