Hi Patryk,
Updating the companion App via the Help / Update the Companion menu item unfortunately didn't seem to work for me (messages appeared in App Inventor saying the install was progressing etc., but nothing appeared in the emultor to be accepted, and the version never updated from 2.65u.)
On googling a bit I found this page: https://community.appinventor.mit.edu/t/aistarter-update-mit-ai2-companion2-to-2-58au/7587. The instructions seemed a bit out of date, but I managed to follow them, and successfully updated the companion app in the emulator to version 2.68u.
Old report in aiStarter:
127.0.0.1 - - [03/Oct/2023 13:32:56] "GET /echeck/ HTTP/1.1" 200 39
Found emulator at emulator-5554
Found companion version 13126500
New report in aiStarter:
127.0.0.1 - - [03/Oct/2023 15:06:40] "GET /ping/ HTTP/1.1" 200 88
Found emulator at emulator-5554
Found companion version 13326800
Unfortunately the same errors as I reported previously still occur.
Cheers, Tim.