AX 2012 Full CIL Compile steps

 1) Stop all relevant AOS server(s)

2) On your relevant AOS server(s) navigate to the following folder (default) using Windows Explorer:
C:\Program Files\Microsoft Dynamics AX\60\Server\MicrosoftDynamicsAX\bin\XppIL

3) Make sure you create a safe copy of the XPPIL folder content to another new local folder on the AOS computer (example: C:\XPPIL_SAVE)

4) Now delete all folders and files inside the folder “C:\Program Files\Microsoft Dynamics AX\60\Server\MicrosoftDynamicsAX\bin\XppIL” but keep the folder “XPPIL” itself.

5) Start all AOS server(s)

6) Run a full CIL creation from AOT. This will create a fresh rebuild of all files/ folders inside the XPPIL folder