@Kolab​ I was compiling my own project, but in my latest post I meant I compiled the example and it does not work.

@Kolab​ Actually, I tried the Nucleo example. The binary is working just fine, I can connect through the COM Port. However, when I generate and compile the project, the compiled binary gives the same error as described.

@Kolab​ Thank you, that worked. However there is no project (.ioc) file for that example and my goal is to enable the COM Port connection for my project.

@stephane.legargeant​ the problem I described happens exactly with the example binary you mentioned.

@stephane.legargeant​ Using the ST-LINK USB the error says "Device under test not responding" in BLE and OpenThread mode but "Could not open COM port" in RF mode.