Error when trying to open a project

When I try to click on a project I get this error.

Have you ever opened any projects on this computer before?

Where are you doing this, at home, at school, or on a public PC?

What happens if you click on this link:
MIT App Inventor

What browser and extensions are you using?

Yes, I was able to open projects last year.
I am on school the school network and computers.
When I click that link it takes me to my projects but still can't open one.
We are using google chrome.

  1. a guess is the school IT department may be blocking the App Inventor 2 communications with the server and they did not block last year.
  2. are you in a class and all the computers are not working or are you working remote (from home or a dorm). In the first instance, talk to your IT department and share this School IT/Network Admins: Information specific to school networks (also helpful for conferences and hotel situations) . If in a dorm, the school might block general access but not from a classroom.
  1. You can see a list of your Projects. That is great. How do you try to open one? If you go to My projects using the MENU, left double click on a project name, the Project should load. Is that what you are doing Nathan?

Yes, I am in a classroom computer lab and none are able to open. I will get with my network admin tomorrow to check on their end.

Good luck. I suspect your IT will need to allow the network to access,, and access (port 3478), and HTTP access from the student's computer to the phone or tablet on port 8001. I think access to port 3478 is the critical part.

Please let us know how it goes.

One in particular, or any one at all?