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LICENSE: C9555E and R208 Error After Uninstalling LIC

Information in this knowledgebase article applies to:

  • MDK-ARM: Unlicensed product


After uninstalling a license ID code (LIC),compiling a project fails. The Build Output window reports the following error message:

Error: C9555E: License checkout for feature LIC0=XX...-.....-..... with
       version 5.0xxxxxx has been denied by Keil back-end. Error code: 1

Another potential error is below:

Error: Q9555E: Failed to check out a license...

(Alternative licensing error codes could be A9555E, L9555E, or Q9555E)

No other changes were made to the computer, application or IDE.


Try one ofthe following:

  1. Revert to MDK-Lite: To downgrade to the MDK-Lite edition with 32KB code size limit:
    • modify the file C:\Keil_v5\TOOLS.ini inside a text editor (e.g. µVision):
      LIC0=TRNxx-xxxxx-xxxxx-xxxxx-xxxxx-xxxxx-xxxxx  [Your Uninstall-LIC]
    • Delete the line starting with LIC0=TRN... or comment it with a ';' character at the beginning of the line.
    • Save and close this file.
    • After a restart of µVision, the Uninstalled license will disappear in the File -> License Management dialog and MDK-Lite will be shown instead.
  2. Re-license If you have already purchased an MDK product, re-license the tools. A new LIC can overwrite the previous license code.
  3. Switch to a new license: If you want to confirm product information, contact Keil technical support. After confirming some information with you, they can discuss the status of a product. Providing a LIC or PSN (Product Serial Number) helps speed up the process.

After taking corrective actions, try building the current project again - the license errors should disappear.




The following Discussion Forum threads may provide information related to this topic.

Last Reviewed: Thursday, April 12, 2018

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