Dynamics AX CIL is not incremental, just mental…

In Dynamics AX 2012, you may some times get this error message when generating CIL code:

Cannot create a record in SysXppAssembly (SysXppAssembly). The record already exists.

I see this quite frequently when generating incremental CIL, to the point where I consider incremental CIL to be thoroughly broken.  Do yourself a favour and do full CIL generation every time, you will save time in the long run from not having to troubleshoot weird and wonderful errors…

Also, I have made it a habit to delete the files directly under the xppIl folder for the relevant AOS when this happens.