Companion Connection Error: See Connection Help

[Erin Elan]

I've been trying to connect App Inventor 2 with my phone using the AI Companion for the past three days, and I get the following error on my laptop every time: Companion Connection Error: See Connection Help as a network error. Things to note:

• I have the newest companion version 2.36 on my phone (Nexus 5X)
• I am on the same wifi network on my laptop and phone (I have tried at three different places with different networks, but always made sure phone and laptop were synced on this)
• I can scan the code (it's upside down, but captures correctly), but nothing happens on the phone. On my laptop, I just get the error.

Any other ideas?

[Taifun]

see the troubleshooting tips here http://appinventor.mit.edu/explore/support/explain-wifi-connection-2.html

Taifun

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Trying to push the limits of App Inventor! Snippets, Tutorials and Extensions from Pura Vida Apps by Taifun. 

[Adam Tokarski]

Taifun I think something is going on as I've been experiencing the same error for the last couple of days.

[Taifun]

please follow the troubleshooting tips  http://appinventor.mit.edu/explore/support/explain-wifi-connection-2.html

for your convenience I will copy the steps in here

Connecting over the Phone Over Wifi Troubleshooting

Try the following steps to troubleshoot your wireless connection.

1. Try to reach http://rendezvous.appinventor.mit.edu from your PC

2. Try to reach http://rendezvous.appinventor.mit.edu from your Android device

3. If the steps above both work, try using the "ping" command to ping to the IP Address of the phone (displayed by the MIT AICompanion in its startup window). If you are using windows, type "ping" + *IP address of the phone* in cmd.exe window, if you are using mac or linux, type type "ping" + *IP address of the phone* in terminal window. Detailed instruction see http://www.wikihow.com/Ping-an-IP-Address

4. If all of these steps succeed and Wireless App Inventor still doesn't work, then there may be a firewall between the computer and phone that is blocking ports 8001 and 9987. If you have a "telnet" program you can attempt to telnet from the computer to the phone on these ports. If the connection won't complete, then there is likely a firewall in place that is blocking connections to the phone 

 If you do not pass step 4, your network most likely looks like this.

did you try these steps? did you get it running? let us know...

[Erin Elan]

I did try these next steps with no luck. My partner, who had been doing just fine with his phone and computer is now seeing the same error as me. Not sure what's happening, but it's consistent at home, work and on other networks.

[Taifun]

My partner, who had been doing just fine with his phone and computer is now seeing the same error as me

which same error? can you be a little more specific?

let's do it together again step by step

1. are you able to reach http://rendezvous.appinventor.mit.edu from your PC?

Taifun

[Adam Tokarski]

Taifun got same issues.
1. Can't reach this on my PC, it's redirecting me to AI main page with Unsafe connection pop-up.

[Taifun]

ok, the page redirects to http://rendezvous.appinventor.mit.edu/explore/

I'm assuming, this is ok, but I will ask MIT, why this happens...

2. Try to reach http://rendezvous.appinventor.mit.edu from your Android device

Taifun

[jis]

Redirecting to /explore/ and seeing our webpage is OK. I put together a better test. Go to:

  http://rendezvous.appinventor.mit.edu/rendezvous/test

(make sure there is no ending slash). You should see "Connection OK" in response.

Of course this just means that the computer can find the Rendezous server, a necessary but not sufficient step.

Things to look for.

After you scan the barcode with your device, does the code dialog box disappear from the computer or does it linger? If you can reach the rendezvous server from your PC but the barcode does NOT go away, it means that something is blocking the device's access to the Rendezvous server. Try going to the URL above from a browser ON THE DEVICE (if possible) to see if you can get through.

If the barcode dialog does go away, but your app does not display on the device, it is possible that something is blocking the connection from the computer to the device itself. This can be the network, it can also be anti-malware or firewall software on the PC. When your computer connects to your phone, it does so on port 8001, a non-standard port. It is possible that an update made to your anti-virus or anti-malware software has decided that this is malware activity and is blocking the connection. It is also possible for browser extensions to do this blocking as well. I have had issues with EFF's "Privacy Badger" blocking connections. Keep in mind that these tools (both PC based and browser based) often change their blocking behavior over time without your intervention.

-Jeff

[Erin Elan]

I don't know what changed, I'm doing everything the exact same on my end, but I am now able to connect with no problems (tried 2 out of the three original networks tried, and both are working). 

Taifun: in the case someone else has a similar issue, I was able to reach rendezvous on my phone and laptop, ping seemed to work, and I don't have a firewall at my home for sure, which is one of the places tried. It only started working this afternoon. I changed no settings, but was able to connect with the QR code immediately. 

[Taifun]

 I am now able to connect with no problems

I'm glad that it worked for you now, happy inventing!

Taifun

[Adam Tokarski]

Doesn't work for me, still getting same error.

  http://rendezvous.appinventor.mit.edu/rendezvous/test is correct in both cases. I'm sure it must be caused by MIT. Turning off Antivirus software doesn't help either.

[Italo]

It is working for me right now, so I don't think it's MIT's problem.

[Adam Tokarski]

But it's not for me.. and this happened for no reason.

[Italo]

Nothing happens "for no reason". If it's working for everybody, except for you, then there's something going on your side that is causing it.

Can you please tell us what you have tried already? Did you follow Taifun's Troubleshooting tips?

What else have you tried?

[Adam Tokarski]

"For no reason', I mean, neither software nor settings have been changed.
Rendezvous indicates correct connection in both cases. Switching off Avast doesn't help too.

Companion Connection Error pops-up all the time.

Update // It seems to be working properly after re-launching WiFI router

[lainey fontaine]

Thank you. I was just about to ask for help too.  But I tried restarting router. And I'm back. Thanks again