AOS crashed when importing XPO

Dynamics AX client crashed when clinking on show details. No message was shown, the application just quit. It was also impossible to reconnect to the Application Object Server because the AOS had crashed as well. When you restarted the AOS, you could easily reproduce this scenario by repeating the above steps.

Sometimes, the following message was logged in the event log on the client, basically informing you that the AX client had crashed:

Faulting application ax32.exe, version 5.0.1000.52, stamp 490c41fb, faulting module unknown, version 0.0.0.0, stamp 00000000, debug? 0, fault address 0×0bbf0b3c.

In the event log on the server an other message was logged, but not every time the AOS crashed:

Object Server 16: RPC error: Client provided an invalid session ID 3

From what I understand, this message is logged when a client sends an RPC request to a server that has ended the session for this client, which would be the case if the AOS crashed.

Once again, the event log is pretty useless. The real problem lies in the application files, more specifically the Microsoft Dynamics AX Label Index files. These are the files that have the extension .ali. For some reason, one or more of these index files are corrupt, and this causes the import process to fail, and the AOS to crash. At the time, the AOS server was low on diskspace, and that could be the cause of the corrupt index files. Luckily, index files such as ali files can be deleted when the AOS is down, and will be rebuilt when the AOS is started.
After all label index files were deleted, and the AOS restarted, the xpo could be imported, and the AOS didn’t crash anymore.

So, when the AOS crashed when you are trying to import an xpo file, stopping the AOS, deleting the ali files from the application directory and restarting the AOS might be the solution