Please try the steps below to see if your connectivity issues resolve.
1. Proxy and Offline Mode
Go to the Settings menu in the Uplay PC client by clicking the gear / cog icon in the upper-right of the window. Once there, click on the Network tab. Then make sure that "Always start Uplay in Offline Mode" and "Allow Uplay to use a proxy connection to access the internet" are unchecked.
Save the settings, and then restart the client to see if the issue persists.
2. Software Conflicts
Try updating your Windows Firewall, as well as updating the firmware for your home router. If updating these programs does not resolve the issue, you may need to temporarily shut-down the associated programs or bypass the router and establish a direct connection to your modem.
You can also temporarily disable your anti-virus, anti-malware, firewalls, and any other applications that are affecting your network traffic before testing the game. If you can determine which application is configured too strictly, you can then add the appropriate exception or allowance to that application to allow Uplay to communicate freely on your local network.
Internet Connection Sharing (ICS) and Virtual Private Networking (VPN) applications can also be conflicting with the game, and you will want to disable these applications to try to resolve the issue.
3. Port Forwarding
If it is not possible to shut-down your firewall you will need to configure your router and/or firewall to forward the following network ports:
Uplay Required Ports
TCP: 80, 443, 13000, 13005, 13200, 14000, 14001, 14008
Heroes of Might and Magic III - HD Required* Ports
TCP & UDP: 8766, 27015, 27016
*Each Multiplayer match requires a host computer/server. If ports are not opened to allow server creation, other players will not be able to join the host server
Directions for configuring network ports are specific to the software and hardware being used, and can be found by visiting the manufacturer's website.
Please visit https://support.ubi.com/en-US/faq/article/000024619 for more information.
4. Background Applications
You may also encounter problems due to applications running in the background on your computer system. When playing Ubisoft games, please be sure to close all running background applications before starting your game. You can find the steps for this listed below.
- Open your Start menu and look for Run (Win XP), Start search (Win Vista), or Search programs and files (Win 7).
- Delete anything on the Open line that you find there, type in MSCONFIG and press the Enter key to bring up the system configuration utility.
- Look down the list of startup items (not the tab labeled Startup), and choose Selective Startup if it is not already selected. If you don't see this, make sure you've clicked on General near the top of the window.
- Once you've chosen Selective Startup, uncheck 'Load Startup Items'.
- Once you're done, click Apply & OK, and let it reboot your computer.
- Once restarted, make sure that any application that affects your local network is disabled.
Try running the game again. If the game loads and seems to be working, the problem is most likely related to one or more programs you have scheduled to load with Windows.
Note: Keep in mind that this is a temporary solution, and any changes can be reverted by returning to the MSCONFIG utility and re-selecting 'Normal Startup".
5. Restrictive Networking Environment
There may also be certain restrictions set by your ISP or network administrator. If you continue to have trouble, please contact your ISP or network administrator for details on any specific restrictions on the previously mentioned network ports.
6. Local DNS
If you are still having connection problems, you will want to try flushing your DNS and resetting your Windows hosts file.
Reset hosts File