This is a persistent problem. Despite my internet connection being perfectly fine I consistently get disconnected from Voobly every 30 minutes or so. I've run network and game diagnostics and everything comes up fine. Whenever I get disconnected this is the error I get:

"Network Connection Error [Code: 10000001]. Connection errors are typically caused by a temporary server outage, a firewall, or a problem with your internet connection. If it's been a long time since you've connected to Voobly it's recommended that you redownload the client from the website."

And for every game I've played since this stated being an issue have ended after about 13-30 minutes with either a "out of sync" or simply a disconnection.

These are the errors that show up in the game room:

<Waiting for the host to start the game...>
<Connection to 'Dark_Kingdom' is not responsive (failure: peer check)>
<Lag Warning: Lost direct connection with Dark_Kingdom. Traffic to this user will go through the fast proxy server. If you have trouble connecting with many different users you have a problem! To resolve this, it is recommended that you forward a port in your router for UDP port 16000. You are also advised to run the Network Diagnostic Tool>
<Connection to 'Dark_Kingdom' is not responsive (failure: peer check)>
<Lag Warning: Lost fast proxy connection with Dark_Kingdom. Traffic to this user will go through the slow proxy server. If you have trouble connecting with many different users you have a problem! To resolve this, it is recommended that you forward a port in your router for UDP port 16000. You are also advised to run the Network Diagnostic Tool>
<Connection to 'Dark_Kingdom' is not responsive (failure: peer check)>
<Connection to 'Dark_Kingdom' is not responsive (failure: peer check)>
<Connection to 'Dark_Kingdom' is not responsive (failure: peer check)>
<Connection to 'Dark_Kingdom' is not responsive (failure: peer check)>
<Connection to 'Dark_Kingdom' is not responsive (failure: peer check)>

Thanks

Warning: Long post coming up

Okay lets go step by step and start from the end.

Talking about the game you mentioned, was that a 1v1 game? When you see 'Connection to XXXXX is not responsive' It is likely that either you or the player in question lost his connection. It is also common for players to reconnect back after a momentary disconnection (minor packet loss, not involving a complete drop in connection or change of IP). If however, you are/were playing with more than 1 players, then you can almost be sure of who the culprit is. This is because when you drop, you will lose connection to every other player. This means you will see those connection errors for every player playing that game (implying it's you who has the problem). I would also suggest that you enable time stamps in Voobly settings so you know when exactly in game did you or a fellow player had a dorp in connection. Time stamps can be enabled from here:

Moving on,

Network Connection Error [Code: 10000001] typically happens when you lose connection to the Voobly server. This usually happens because of a problem on your side but can rarely also be caused by an issue with the server. Though keep in mid that the later is extremely rare and in most cases you won't be the only one affected if that's the case..

So what do you do to fix this problem? Well the answer is simple, you have to narrow down the problem and try to pin point the exact cause of the issue. Based on your inputs, below are some of my suggestions:

1. Reinstall the game. Make sure you use a legitimate copy of the game. Pirated copies can sometimes contain altered data files which may cause your game to go out of sync.

Please follow the steps mentioned here to perform a clean installation of the game:
http://support.voobly.com/display/vkb/KB1019+Clean+installation+of+Age+of+Empires+II+with+the+latest+patches

In case of HD version,
Please follow the steps mentioned here to perform a clean installation of the game:
http://support.voobly.com/display/vkb/KB1054+Clean+installation+of+Aoe2HD+with+compatibility+patch

2. Open UDP port 16000 on your router (in case you haven't yet already). This helps you maintain a direct connection to all players in your game room avoiding the need for Voobly to redirect game traffic through its own proxy servers thereby eliminating possible lag. You can do this by logging into your router and setting up port forwarding to your computers IP.

3. Make sure you do not have any pending windows updates. Ensure your antivirus and antimalware is up to date. Run a full system scan to eliminate any possible threats. I would recommend malwarebytes.

4. Set an exception for Voobly and AOC in your security applications (Firewall, Antivirus)

5. Contact your ISP and check if they have any ongoing outages. It may also help to test your games on a different network (if possible). Example: A neighbours wifi or your mobile network. You can then test and see if you are still getting dropped or come across the sync errors.

Note: Voobly also has a live help lobby which is usually manned 24 x 7 where we are happy to assist players like you in real time. Feel free to join the lobby if you have to.

God luck