VEXcode V5 Cloud Compiler Error on Chromebooks

My students are getting an error when they try to download their programs onto their V5 brains. This is frustrating the heck out of my students, me, and IT because who gets the error appears random (one day 5 kids will have the error and 5 other kids can download…the next day it’s a totally different mix of who can download and who can’!)

My IT department is telling me that the following sites are unblocked for students:

Any ideas? Anyone else having the same issues? My robotics class is STUCK until we can get this fixed (oh, and to the peole saying “just buy laptops, not chormebooks”…that’s not an option for a small town school)

Thank you!!

Try making sure that “” (TCP protocol, port 5637) is open: it’s the cloud compiler for Blocks.
Anyone using python needs to open the linter, which is at on the same port.

We found a pretty simple solution to this, although it might not work for everyone because of how silly it is. For some reason changing our wifi network to our other school wifi solves it.

When you say “make sure it’s open” do you mean make sure that IT has it unblocked? Or that the students have a tab open at that website? Or something else?

One kid has had success changing to our guest wifi, but that doesn’t seem to work for anyone else. Thanks for the idea, though!

IT should have the port unblocked.
About the guest wifi change; a lot of schools use a proxy that is only enabled on the main, secured wifi, and the guest wifi is less restrictive. Are you using a website-blocking chrome extension, like CKAuthenticator?

We are sorry for the inconvenience this has caused you.

In preparation for supporting future features in VEXcode we have had to enable secure connections to our cloud compiler servers. This change required that we also change the URLs and ports used by all VEXcode applications 2.3.0 and later.

The new cloud compiler information for VEXcode V5 2.3.0 and later is

Blocks / C++ Compiler:
Python Linter Service:
Port: 5637
Protocol: TCP

You can find more details in the KB at