Couldn't debug via ST-Link

[curiae]

Hello,

Just before I tried to debug STM32L052 via ST-Link but following error occurred.

The error message is as following.

It's strange that I could debug and run with same project yesterday and nothing is changed as for project.

What is the problem and how to solve it?

Thanks,

STMicroelectronics ST-LINK GDB server. Version 7.9.0
Copyright (c) 2024, STMicroelectronics. All rights reserved.

Starting server with the following options:
Persistent Mode : Disabled
Logging Level : 1
Listen Port Number : 61234
Status Refresh Delay : 15s
Verbose Mode : Disabled
SWD Debug : Enabled
InitWhile : Enabled

Target unknown error 19

Error in initializing ST-LINK device.
Reason: Unknown. Please check power and cabling to target.

[Imen.D]

Hello @curiae ,

Are you using your own customized board or ST board?

What happens if you connect in STM32CubeProgrammer ? Try to connect through STM32CubeProgrammer and set the connection mode to "Under Reset" and perform a "Full Chip Erase" to clear the flash memory.

Check the debug pins are free, reserved for Debug: How to solve debugger connection issues - STMicroelectronics Community.

If the issue is not resolved, check (through your STM32 schematic and Datasheet) the basic pins and the power supply schemes that are within their specified voltage ranges : VDD, VDDA supply, VCAP pins...