Android: Connection could not be established

Hiya,

I've installed the TeamViewer app in my android tablet, (Samsung Note Pro12.2 SM-P900), however, it never seems to be able to connect to teamviewer at all. On the Connect page, entering a valid TV ID results in the message "A connection could not be established. Please check your connection and try again". Similarly, on the Computers tab, entering my user name and password results in "Sign in failed. Please check your connection and try again". The tablet is definitely online, and I have tried reinstalling the app but to no avail. I can confirm that I have also tried the above on my mobile device and that works fine on cellular data and Wi-Fi. What can I do to fix this issue? Thanks!

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Comments

Kingklave

So not helpful julia

jagsjim

Thank you for the response. Yes I used to connect with my Android and I can still connect with my Windows 10 laptop via WiFi. I will reach out to AT&T and see if they can assist.

Dennyca

Ask your ISP to watch a session you are trying to initiate. They changed a setting in the cable modem which allowed me to connect. Did you connect before through the same wi fi connection previously?

jagsjim

Just checking to see if anyone came up with a solution.

Opening the port was not successful.

Activating UDP protocol then Restarting phone wasn't successful either.

I turn my Wi-Fi off when I "HAVE" to access another computer, but I hate wasting the data.

KoenPeer

Hi Everybody,

Opening port 5936 is not an option.

I tried multiple phones of different brands, on the same WiFi network. Some worked fine, some cannot connect. So this is not a problem on my router or modem, otherwise all phones could not connect. i have seen some phones have UDP activated on default, some do not.

None of the samsungs activated UDP protocol, where iphones all activated them.

Here is a (very simple) solution that worked for me.

Open teamviewer --> on the top right go to settings --> activate UDP protocol --> Restart phone.

Hope it helps some of you

Good luck.

Julia

Hi all,

Thank you for your feedback here.

I can only repeat myself - port 5938 has to be open for outgoing connections to get a connection on the Android app. This is the only port at the moment and it's not a bug but an expected behavior.

If you would like to improve this, please feel free to create a feature request in our "Ideas" board and explain the background for it

Ankit110

I was having the same issue, I uninstalled all other TeamViewer apps and the installed only TeamViewer for remote control. This seemed to have solved the problem. Maybe other TeamViewer apps using same port?? I don't know yet but this should be fixed by TeamViewer team.

atomia

All my mobile devices can not connect on WIFI. If the port is the problem, why cant the app have an alternative port which can be used? Obviously we are not network admins and have no control of the wifi's ports that we will be using! This port issue is a BUG!

Peeer

I have more information about the error:

Device Samsung Galaxy Tab A (216)
Adroid 7.0_0009
Have tested Teamviewer 13, 12 and 9, same problem with all,
OK in datatrafic 3G, 4G
Network error i WIFI,
All other smartphone with older Android and computer there is no error.

Is there a bug/ error i Android 7.0 with Teamviewer over wifi?

Peeer

Same problem here in android 7, no network, no problem in older version of Android or in iPhone.

It is just in wifi, no help with differnt dns settings or to reset app data.

Mobil data is working, but can not be used inside the local network, must have acces to other devices.

This seem as a bug in Teamviewer or in Android 7. Need help to solve this.

kim121

just how do you make sure that port is open?

Dennyca

I had this exact issue with 3 of my android tablet devices using Comcast XFINITY internet. I went on a chat session with a rep and in 5 minutes, he changed a setting in the cable modem or provisioning and voila , all my devices started working! I did mention the port 5938 number that was giving the error. So apparently this is known issue that perhaps is keeping the network safe from hackers? Anyway , reach out to your ISP Good luck D in CA

RalfFL

Hi, this ist Ralf from Germany.

I've the same problem, on wifi connection teamviewer don't work. We are in the same network, no port control!

I turn on mobile data and teamviewer WORKS FINE. From Samsung P905 to a notebook in our lan.

What's now?

Julia

Hi timjim,

You have to change the ports in the network where the device is connected to.

timjim

Should I set this up from my Android device? I didn't see the option for setting ports.

It's a little strange as when I use Teamviewer from my PC, it will connect to the remote computer fine when on the same wifi network that the Android devices struggle on. Thanks and regards.

Julia

Hi timjim,

I am pretty sure that the problem is port 5938 - and there is no setting for this in your account.

timjim

Thanks for the reply Julia. Unfortunately, I don't have control of the ports on the institution network. However, I notice the same issue with my connection at home and also on public wifi hotspots in town. Could it be a setup issue on my devices?

Julia

Hi timjim,

It seems like there is a problem with the wifi and not with the mobile network.

TeamViewer on Android can only connect throught port 5938 - please make sure that this port is open for outgoing connections in the network.

timjim

Just a little extra info - I'm still having the same problem. On the sign-in menu, the sign in wheel animation goes around but nothing happens. If I switch from using wifi to mobile data in this time, it connects and goes through to the list of my computers. However, on switching back to wifi mode, it disconnects and dumps me back to the sign-in page. Thanks, Tim

timjim

Apologies for the double post - I want to add that the same error appears to be present on my Android phone when connected to WiFi. It only seems to find a connectionwhen on mobile data. The app on both the tablet and mobile device do not appear to be connected at all when using (working) WiFi.

I am currently unsure if it uesd to work on WiFi (as I mentioned in the first post), or if I simply mistook it, and it was actually working on mobile data.

Thanks and kind regards

timjim

Dear Julia,

Thanks for your message. I'm in Japan. I have tried it on several ISPs, including George [removed per Community Guidelines] and the university network on eduroam.

I have just tried the password reset. However, it still comes up the same. The message appears instantaneously - as if it is not even checking.

Kind regards.

Julia

Hi timjim,

In which country are you located and which provider are you using?

Please try the following for the sign in error:

Go to our Management Console and click on "I forgot my password" - after that follow the steps in the email you will receive and try to sign in again.