Can someone please help me?
Let us try and guess so far:
- You are trying to download a file, from somewhere....?
- You are using/trying to use the CustomWebView extension?
- You are trying to do this in the AI2 emulator ?
How about showing us your blocks and html, and a full url of the file you are trying to download ?
The companion update process requires that the emulator can access the Internet and reach the App Inventor server at ai2.appinventor.mit.edu. When this happens, it is usually due to a firewall configuration preventing emulator.exe from making outgoing internet connections. If you're doing this in a school environment, you will probably need to talk to your school IT to make sure that the emulator process is on the allow list.
I should read more carefully 
Thanks, I'll try that.
ok now this is popping up:
Hmm. Based on the error it seems like the emulator cannot make outgoing DNS requests (port 53). You may need to pass that information to the IT team since my guess is that the allow rule they put in place was a bit too restrictive.
thank you.