In some large implementations, you can get into situations
where every other AOS tries to build the axapd.aoi index file, if the
application folder does not contain an axusr.aod file.

 The Dynamics AX administrator may notice the following
errors in the application event logs:

Object
Server 01: Failed to create file axapd.aoi. Error code was 32

Normally the application folder will always contain an
axusr.aod file, even if it is 8KB, which is an empty layer file.  The 8KB
axusr.aod file is created by default when a user logs into the USR layer.

Depending on the way you deploy new code from your
development environment to your production environment you may not always have
the axusr.aod file deployed to production.  In one customer's situation, their
deployment process was to delete the "empty" axusr.aod file before
promoting the code to production. 

In another case in the development environment users
(developer) only logged into the VAR, or CUS layers and no one ever logged into
the USR layer, so the file was never created.  Their process was to rename
the existing production application folder and copy in the new development
folder using the same application name.  In that case, the axusr.aod file
was only created when a normal user first logged into the production
environment.