Whenever I try to connect the companion it comes up with an error like in the screenshot. I have reinstalled the companion APK, and still the same. I've got no idea what to do.
Show the companion screen before you enter the code
I do. It doesn't matter which project I choose to connect, it comes up with a different error.
Yes, I also noticed a problem in Companion when loading projects with extensions.
That's strange. When I connect with the 6 digit code rather than the QR code, it loads correctly. But then if I disconnect and reconnect using the QR code, it brings up the error again.
Something must be wrong with the QR generator.
The companion shows its version at startup.
Still guessing here.
P.S. The current version should be 2.73 or 2.73u, at ai2.appinventor.mit.edu
Yes 2.73u is the one I'm using.
I cannot connect with 6 digits now. Totally gone wrong.
I need HELP!!!
what happens if you remove the bodymindpower extension?
That specific extension seems to be the issue.
Problem could be with your IP and slow response too.
Have you tried using this link code.appinventor.mit.edu
Removed all bmp extensions. No difference. Removed all my apps from the server bar 3. Removed any extensions I could. Used @Anke's deleteAssetsCompanion to delete what I could. Still having problems. ALL extensions seem to be the problem.
Would starting a new account help?
I logged in using a second Google account I own. Using the QR code. the same problems occured. Using the 6 letter code I was able to log in. Mind you I uploaded a simple AIA file from my comp. it seems the problem still exists with a different account.
If you are testing an aia project that contains an extension with companion 2.73/2.73u on an Android <14 device, then it will not load:
Try an aia project without any extensions
This is not true. For me the resources and extension do not load on android 14.
Is that on a Samsung ?
No, Chinese POCO.
Well, neither of you have provided full specs and environment, so it is like trying to find a black cat in the dark 
My Device is A13 Android 14