Not able to connect AOS despite of no change in the setup

Hi All,

Thank you for reading the post. I was able to connect to the AX-09 AOS until yesterday and everything is very much unchanged today, but when I am trying to connect I get error message as “connection with the application object server could not be established.” I am able to access the server-machine with the help of “Remote Desktop Connection” and login to Axapta session with the help of the essential credentials. Can you please suggest me the reason?

Any suggestions?


Start AOS service from Admin Tools > Services.

Thanks & Regards,

Mehul Thacker

Hi Mehul,

If you mean “Dynamics AX Object Server 5.0#########” then its already started/ restarted several times.


This is a very common issue and was discussed many times here. Did any change happen in your network such as domain change, firewall added etc.

Also if you do a search here, you will find useful info for resolving this error.

Hi Harish,

Thank you for your suggestion. The issue was resolved by changing the firewall properties (Control Panel\All Control Panel Items\Windows Firewall → Advanced setting → Windows Firewall Properties-> Domain Profile tab → Inbound connections (change from default block to allow)). But I still don’t understand why did it work for all past days and suddenly stopped working since y’day? I have confirmed that no change in the security policy/ firewall settings/ network settings was done. And I must do further research to bring the settings back to default/ recommended value. I will update the thread once I get any lead, please share your views if you know anything about it.

Hi Abinay,

If firewall is on, these problem may arise. Also, some times due to network properties changed, this will happen i.e ip address change . Also, sometime in cofiguration, port number changes will also lead to this problem. So check all possibiities…If u are using a client machine and trying to connect AOS, it the error is coming, try to ping with server to check whether any communication is there between client and server…

thanks and Regards,


Hi Kevin,

Thank you very much for the suggestion.

To be very frank, it’s a test server and nobody has access to it, and I did no change in any of the configurations. Still I will check if any windows update was installed recently and update here.