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µVISION DEBUGGER: "Cannot Access Target" Message Using NXP CMSIS-DAP

Information in this knowledgebase article applies to:

  • MDK V5.22


While debugging a dual-core NXP LPC54114 device using the on-board CMSIS-DAP driver, when starting the debugger or continuing to run from a breakpoint, the following error message might display.

Cannot Access Target - Shutting down debug session


If this message displays when starting a debug session, open your µVision project and make sure the Verify Code Download checkbox (Options for Target, Debug tab, Settings button) is not checked.

If this message displays after clicking the Run button, the attached update for MDK V5.22 will correct this. To install this update:

  1. Download the updated CMSIS_AGDI.DLL file attached to this Knowledgebase Article.
  2. Close all instances of µVision.
  3. Install this file in the C:\Keil_V5\ARM\BIN\ folder. If you installed the MDK tools in a folder different from C:\Keil_V5 (the default), substitute that drive and folder name for C:\Keil_V5.
  4. Restart µVision.


This is corrected in MDK V5.23


Request the files attached to this knowledgebase article.

Last Reviewed: Friday, January 13, 2017

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