Hubert,
After your response (Route Admin Panel | Husarion), I deleted admin and followed instructions to reinstall.
First, after this line
$ husarion@husarion:~/husarion_ws/src$ curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash -
[/quote]
Second, when i got above error yesterday, i found this link (Apt update - invalid signatures - fresh system reinstall) for it.
First command is $ su root. Password did not work.
Then, second comment said that it should be “sudo su root” not “su root”.
Three, followed the rest with your suggestion, and it works with command:
$ roslaunch route_admin_panel demo_rosbot_mbed_fw.launch
Thanks
Vineet