[2021] UPLAYdoesn't sync

Hello tourque313, thank you for getting in touch and sorry for the delayed reply.

There are a few things you can do to fix the runtime error you receive.

First of all, when you have the game launched, please check Task Manager in your Windows settings to see how much ram you are currently using on your system.

As well as this, please check to see if you have any other software running under the processes tab, and the start-up tab, as they may be consuming your ram.

Software such as -

Full Screen Game Overlays
VoIP and Chat services
RGB controllers
Overclocking Software
Hardware monitoring
Streaming software
Peer to Peer software
VPN

A more detailed list of this type of software can be found near the bottom of this article and contains instructions on how to disable them and clean boot your PC - https://support.ubisoft.com/en-GB/Article/000063761

Please let me know how you get on after checking you have no extra programs running in the background, performing a clean boot, then launching the game.