Multiple AX 2012 client instances at the same time

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The installer doesn't support multiple instances. Is there any workaround for this? We have multiple AOS with different versions and the client is installed on the same machine. Every time we start the client we get "Internal version mismatch" warning in the event log.


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  • Hi Petr,

    When you install multiple versions of AX on one machine, you have to know that some values are stored in the windows registry. There can be only one default version.

    You can handle this by creating shortcuts opening ax32.exe (from a specific directory) and the appropriate configuration file in one link.

    Another possibility is to use multiple machines per version, if possible of course.

    If you plan to run one major version and multiple SP or CU versions you will definately have a challenge...

    kind regards,

    André Arnaud de Calavon  |  Microsoft Dynamics AX Solution architect  |  My blog  |  My company

    This post is my own opinion and does not necessarily reflect the opinion or view of my company, Microsoft, both its employees, or other MVPs.

  • ther eis alot of useful information here:

  • Do not mix versions of the kernel of the client and the service itself. If your service is using a kernel with as an example version 6.0.1108.2423 (AX2012 RTM CU4), then you should use a client with the same version. Any other scenario is not supported by Microsoft.

    Do not mix AX2012 and AX2012 R2 on the same machine. They use a different version of the binaries ( vs

    Kernel versions will increase the buildnumber (last digit) when installing updated CU or hotfixes. These will by design be backward compatible with the application version, as long as the two first version numbers match (6.0.1108.2423 - CU4 - kernel supports a 6.0.947.61 - CU1 - application version).

    Version numbers:

    More in-depth around Feature Pack versioning:

    If your AOSes are on the 6.0 version, just keep the kernel at the highest version for both service and client. The kernel should be backward compatible with the application code in your various AOTs.

    Tommy Skaue | Dynamics AX Developer from Norway | |

  • Hi Tommy,

    We have AX2012 R2 ( and AX2012 R2 CU1 (6.2.1000.156) on the same machine. When I connect to AOS with AX 2012 R2, "Internal version mismatch" appears in the event log.


  • If I had the time to find the reference, I would, but I can assure you, RTM and R2 is not supported on the same machine. Avoid it or live with the instability and errors.

    Tommy Skaue | Dynamics AX Developer from Norway | |

  • I am having an issue where I have a my 3 clients spread across 3 citrix servers. Those client kernel builds are 6.2.1000.1437. I use the citrix clients to load balance between 5 different AOSes. One of those AOS has a Hotfix that has increased the Service Kernel to 6.2.1000.3198. I am having frequent crashes with my AOS on 3198, and a fair amount of client crashes. Is it because of my Client and Server Kernels not matching? If so, can I upgrade the clients with the hotfix and then they would be backwards compatible with the 1437 AOSes?

     Zachary James | Microsoft Dynamics AX Technical Consultant |