TeamViewer version 12-14 can't establish connection to servers (all of a sudden)

I've used Teamviewer 14 for long time, and just all of a sudden it's unable to connect to servers. I can't even check for updates via App and log into account.

System is Windows 10 (bootcamp MBP mid 2018)

Log files says something about dns and socket errors (flooded with the same strings):

2019/06/27 18:34:29.479  4440  5784 S0!! CHttpConnectionOutgoing::ResolveDNSName: resolving DNS name failed, status = Failed, HTTP response code = 0, URL = 'http://router8.teamviewer.com/cname.aspx'
2019/06/27 18:34:29.479  4440  5784 S0!! CHttpConnectionOutgoing::HandleResolveDNS: empty address, m_ConnectionState=0
2019/06/27 18:34:29.480  4440  5776 S0!  CProcessCommandHandlerKeepAlive[17236]::HandleKeepAliveConnect(): Connect to KeepAliveServer failed
2019/06/27 18:34:29.480  4440  5776 S0!!!KeepAliveSessionOutgoing::ConnectFailureHandler(): KeepAliveConnect to router8.teamviewer.com failed
2019/06/27 18:34:29.481  4440  5776 S0   Waiting 1 seconds to connect to KeepAlive again
2019/06/27 18:34:30.481  4440  5796 S0   CKeepAliveClientClient::StartConnect(): Protocol 8 proxy -- IP router8.teamviewer.com
2019/06/27 18:34:30.481  4440  5796 S0   Activating Router carrier
2019/06/27 18:34:30.481  4440  5796 S0!!!CTcpConnectionBase[17237]::HandleResolve(): Resolve failed, router5.teamviewer.com:5938, Error: system:11001
2019/06/27 18:34:30.481  4440  5776 S0!  CProcessCommandHandlerKeepAlive[17237]::HandleKeepAliveConnect(): Connect to KeepAliveServer failed
2019/06/27 18:34:30.481  4440  5776 S0!!!KeepAliveSessionOutgoing::ConnectFailureHandler(): KeepAliveConnect to router5.teamviewer.com failed
2019/06/27 18:34:30.481  4440  5784 S0   CKeepAliveClientClient::StartConnect(): Protocol 4 proxy -- IP router5.teamviewer.com
2019/06/27 18:34:30.481  4440  5784 S0   Activating Router carrier
2019/06/27 18:34:30.483  4440  5776 S0!! HttpRequestImpl::CurlFinished(): curl request failed: Couldn't resolve host name (6), Could not resolve host: router8.teamviewer.com
2019/06/27 18:34:30.483  4440  5776 S0!! Port443Connection::RequestFinishedCallback: failed with HTTP status code = 0
2019/06/27 18:34:30.483  4440  5784 S0!  CProcessCommandHandlerKeepAlive[17238]::HandleKeepAliveConnect(): Connect to KeepAliveServer failed
2019/06/27 18:34:30.483  4440  5784 S0!!!KeepAliveSessionOutgoing::ConnectFailureHandler(): KeepAliveConnect to router8.teamviewer.com failed
2019/06/27 18:34:30.484  4440  5796 S0   CKeepAliveClientClient::StartConnect(): Protocol 2 proxy -- IP router8.teamviewer.com
2019/06/27 18:34:30.484  4440  5796 S0   Activating Router carrier
2019/06/27 18:34:30.486  4440  5772 S0!! HttpRequestImpl::CurlFinished(): curl request failed: Couldn't resolve host name (6), Could not resolve host: router3.teamviewer.com

Portable version 14 on this PC has no connection as well.

I tried to reinstall full version 14.

Tried install version 13.

Tried change app folder name and manually cleanup all dependent settings in user folder.

I've installed AV software for the first time and scanned PC for viruses. I have bult-in Windows real-time protection settings at lowest possible.

I have firewall disabled globally. However, I tried to allow all inbound/outbound actions for TV app via Windows firewall.

I did reset all Windows network settings with reboot.

I tried flush dns and some netsh commands.

I tried to use 8.8.8.8 dns servers.

I tried to use different WiFi hotspot with my iPhone carrier.

I tried to use OpenVPN connection.

I tried to drag and drop TV14 portable into VMware machine on this Win 10 and it has connection with no issues.

The second laptop on Win 7 with TV13 installed within the same WiFi network works fine.

iOS TV app within this WiFi works fine.

I tried to launch old portable versions of TV and 10-11 version works fine to my surprise.

12-14 has no connection.

What the heck, could anyone help? Thanks.

I have disabled Windows 10 updates with 3rd party tool (due to Windows waking up my MBP in carrying sleeve or at night, lol) and latest updates cycle was checked at 07.05.2019.

Local connections via private IP is still possible (TeamViewer sidebar shows iOS client connected, but iOS shows black screen with 'Connecting...', not sure why).

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Accepted answers

TVscale

Well, I had to update installation from 14.6 > 14.7 and it looks like the last hammer hit on the code was made. IT WORKS!!!!!!!!!!!!! IT'S **beep** MIRACLE!

All comments

TVscale

Well, I had to update installation from 14.6 > 14.7 and it looks like the last hammer hit on the code was made. IT WORKS!!!!!!!!!!!!! IT'S **beep** MIRACLE!

TVscale

I've tried w/ and w/o IPv6 checkbox in wifi adapter settings.

TVscale

I still have no clue what the heck is going on, but I just installed Fiddler network debugger and if I launch first Fiddler and then teamviewer -- it works without issues! But if I close Fiddler and launch TeamViewer, then again issue persist.

Should you think I am somehow dumb -- no, I'm extremely advanced PC user, and this issue drives me crazy.

btw connection via private IP still shows black screen

TVscale

Thanks for telling. I have IPv6 checkbox disabled in adapter settings, IPv6 disabled in Google WiFi router and in my ISP control panel.

TVscale

I tried to listen all interfaces with Wireshark, and when TeamViewer starts and tell me there's no connection -- there's absolutely zero packets with all interfaces. So TeamViewer somehow has no access to network activity at all.

My system is almost clean and has no strict policies on anything, I have UAC disabled etc. I even can monitor breath of apps looking at packets on interfaces as there's no apps installed. So don't think there's something which I'm not telling or I forgot about.

TVscale

I tried TeamViewer Cleanup Tool which cleaned up all hidden teamviewer traces including machine id, but it has no results on connectivity.

Audit of Windows events log shows everything fine. Not a single app or package install since last check of updates (09.05.19), no dependent errors prior to teamviewer stopped working.

I tried to enable Windows updater and install all new Windows updates.

I tried netsat command to see all active connections in case of malicious hidden teamviewer rat taking over teamviewer connection, but this theory failed.

WEIRD!

TVscale

This issue is still persist even with lots of updates.

TVscale

I've investiagted the log files again and it seems that this line is the key

2019/10/07 00:51:10.226 4276 5012 S0 CKeepAliveClientClient::StartConnect(): Protocol 4 proxy 127.0.0.1:8888, user= IP router3.teamviewer.com

In the first post, the log files contained a word of Proxy, but there was no details about 8888 port. Seems it have changed with the recent updates. I'm surprised that help on official forums is sort of garbage.

Moving next, the only app I have which used 8888 port is Charles with its built-in proxy options. It can listen on 8888, but in addition there was a switch to 'enable Windows proxy', which force redirects all the trafic. I used it once, but once disabled, it should have no impact on the system. However, it seems this crooked TeamViewer don't think so?

I tried to check its Proxy settings in Extras > Options and proxy option disabled.

I'm wondering as to why I do not see its attempts to connect to 127.0.0.1:8888 in netmon applications. However, if I launch Charles, the TV instantly jumps into his 8888 port, while the option of 'Windows proxifying' is disabled.

I scream to gods!

I changed listen port to 8889 in Charles and TeamViewer of course can't connect.

I specified localhost:8889 proxy in teamviewer settings, but it still has no connection and log files keep showing it wants the 8888 port. I even tried to change to localhost:9999 and enable Socks proxy in charles on 9999, since I do not know if teamviewer wants http or socks proxy via its settings.

I have Windows 10 proxy disabled in network settings, as well as LAN proxy in IE settings.

TVscale

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\TeamViewer

ProxyAutoList

127.0.0.1:8888;;
127.0.0.1:8889;;

I don't know how this parameter is created and where these values are came from.

I've deleted it but it doesn't help. Seems this values copied somewhere deeper.

TVscale

This piece of **bleep** started working.

Today I rejoice, as if I had won the Trojan War. Allāhu akbar!

TVscale

I hastened to make a statement.

Full installation of TV14 is able to connect to remote servers, however, it can't handle LAN connection. Log file show this:

2019/10/25 09:51:43.153 4856 5764 S0!! CTcpConnectionBase[15]::HandleConnect(): Connect failed to dest-ip 192.168.0.11:5938 with error 10038 Ñäåëàíà ïîïûòêà âûïîëíèòü îïåðàöèþ íà îáúåêòå, íå ÿâëÿþùåìñÿ ñîêåòîì

I tried to recover this message with broken codepage (I'm speechless why teamviewer tried to log something in OS language and failed to do so). So the message says 'An attempt was made to perform operations on an object that is not a socket'. Go figure what it does mean.

TV14 portable version is fully working, but it was already so, when I deleted registry keys about Autoproxy. It takes him about 5-10 seconds after launch to go through diffirent methods of connections, and then it shows 'ready to connect'. It can handle external and local connections just fine.

Aaaarggh!!!!!!!!!!!!!