Connection with Application Object server could not be established

Hello Everyone,

We are using AX 2009. we have a distributed environment with different servers for AOS, SQL Portal Reporting etc.

We have 7 affiliate offices who are also using the Dynamics Application from our server.

We have done two way forest trust between domains so that the users at the affiliates can use the Application from our office.

Additionally, each affilliate office and also our company has different sites where domain controllers have been installed.

recently, I had to demote one domain controller at a site office of our company, After this the users from affiliate offices cannot use the Dynamics ERP application. They get the error

“Connection with Application Object server could not be established”

Please advice .


Check the the AOS is started or not. if not start AOS.

and check the client configuration file for TCP/IP port Number is the same wt u have given in server system client configuration TCP/IP Port Number.

I hope may help u…


Also try to run the “Services”…

Services → find & click Microsoft Dynamics AX 2009 → click Start

Wait untill it finished running then try again to open your AX.

(Services - Starts, Stops, Configures Windows Services)

I hope it could help.



make sure that the right database found in SQL is linked to the AOS correctly

You can make file start.bat and stop.bat in your desktop to make easy start and stop your Ax AOS.

example :

net start AOS50$01

then save as type start.bat

net stop AOS50$01

then save as type stop.bat

I hope this can make easy to start and stop AX AOS…

learn together

how can we check that?


just execute the batch file from the command prompt.