There is a project, last updated in Nov 2020, that needs a few changes. It is written in C#, using VisualStudio 2017. When I started the Raspberry recently, with the original SD card which I used for developing, the Raspberry could not find any network, - LAN nor LAN. I re-installed the IoT dashboard, flashed the OS to a new SD card (Sandisk ultra, 16 GB), replaced network cable, but still no network. What's different: I use VisualStudio 2022 now. But that can not have an impact on the Raspberry which had been untouched for 2 years - after re-installing the newest version of IoT dashboard it could.
I tried the Raspberry with Raspbian OS and it showed all available networks, so it is not a hardware issue.
Are there any known issues? It is not a Raspberry Pi 3B+, which is said to be not supported. I would be grateful for any hint!
Thanks in advance!
Problem solved. The firewall blocked IoT-dashboard. Obviously one has to format and re-flash the SD card after the firewall allows IoT-dashobard.