Wednesday, March 24, 2010

More information about the AUC file

What does AUC stand for?

AUC is short for Application Unicode Cache.

What is the AUC file used for?

The file contains a cache. Objects of the application object tree from Ax are stored locally, so that they don't have to be read from the AOS server over and over again.
So it should speed things up a bit.

Where can you find the AUC file?

This cache file is stored together with the user profile information. And as so it's location varies according to the operating system version used.

You can find it in following folder:
Windows XP and Windows 2003
C:\Documents and Settings\%username%\Local Settings\Application Data

Windows Vista, Windows 7 and Windows 2008

Can you delete the AUC file?

Barack Obama and I agree: Yes you can!
Close your Ax client session, delete the AUC file. The AUC file gets recreated automatically next time you logon to Ax.

How is the naming of the AUC file defined?

In older Ax versions (3 and 4), the filename for the cache file is based on the AOS name, server name etc. In Ax 2009, the name is based on a GUID. The GUID used is the one you can find in the Ax table SysSqmSettings (field GlobalGuid).
As such, watch out with duplicating databases for test purposes. You don't want 2 Ax server instances using the same GUID and as such the same cache file, as this will lead to unexpected results. (Should this happen: Replace the GUID in table SysSqmSettings with an empty one. A new GUID will be created by the AOS at restart.)


  1. unicode? someone must be high. it's user cache.

  2. No, the article is correct.

    The following is from Microsoft's TechNet for AX 2009, at

    "For example, .auc means application Unicode object cache ..."


    "The only exception to above-mentioned naming convention is the .auc file. The client-side application object cache file is named .auc (application Unicode object cache). In earlier versions, it was named .aoc. The new name reflects the fact that objects are now stored in the Unicode format."

  3. You got me on the "Barack Obama and I agree" LOL
    Thanks for the info

  4. Nice post. You can visit following link to get Ax 2012 technical code and error solutions

    Ax 2012 Development and Coding

  5. We have a class that connects an external application with AX.
    This applications calls an AX Class that generates Daily journals.
    The journals are correctly created but sometimes at the start of the month, it doesn't see the actual values of the ledgerPeriod table.
    It throws an error that the period is not open but it's really open.
    It only happens in one of the two AOS. One AOS can see the correct values of the table, but the other AOS see older values.

  6. Subscribe to learn this new technique in Ax . Give like comments and share