Attempting a debug connection to a device with RDP protection gives misleading error message

AHugh.2 · ‎2026-05-18

I just spent some time trying to get a debug session going in VSCode ony to be given the rather obscure error message: "bound doStepConnectToTarget Failed: could not connect (error 138): The system tried to join a drive to a directory on a joined drive."

Eventually I realised what it was - I had enabled RDP protection on the device (STM32C5) so of course it could not connect.

May I suggest that a more appropriate error message is given in such circumstances?

(this is with stlink gdb debugger, latest version.)

Andrew Neil · ‎2026-05-18

This seems to be a generic GDB issue - nothing specific to ST.

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

Nawres GHARBI · ‎2026-06-04

Hi @AHugh.2

this error is shown in two cases

1- outdated ST-link FW , you can update the FW

2- stuck debug process (it can occurs if you unplug the board while debugging), you can kill it from the task manager