Aquiring Token from ACS has failed.

(3) Share

Report

Posted on by DP-06061321-0

Morning,
I wanted to change the configuration of Dynamcis 365 On-prem to communicate with Exchange Online after adding a certificate and assigning the application itself mail server profile(connection test) sees exchange that is link:https://outlook.office365.com/EWS/Exchange.asmx It also sees the user but at the authentication of the mailbox has this error:
Aquiring Token from ACS has failed.
I tried to do the instructions from this link:
https://community.dynamics.com/forums/thread/details/?threadid=2fabeeca-181d-f011-998a-7c1e52189d0f
However, some commands do not work, that is, when running the Set-CrmRecord command there is no such aprameter as -AttributeList. I would ask you to update the intructions or help me to consider the problem.
Thank you for your help.

Categories:

Dynamics 365 general

All responses (2)

Answers (0)

DP-06061321-0 24 on at

Like (1)

Report
Aquiring Token from ACS has failed.

What certificate should be added, should it be the server certificate(domain certificate),SSL certificate, or some other certificate we should add?

After configuring the application and performing the connection test, the second control appeared in green, as shown in the photo below.

All the commands from https://learn.microsoft.com/en-us/dynamics365/customerengagement/on-premises/admin/connect-dynamics-365-on-premises-exchange-online?view=op-9-1 have been executed and entries in the Database have been added.

We do not have Claims-Based Authentication configured-nowhere in the manual was it spelled out that this must be done. We also do not have ADFS which is required to configure this option.

Check ACS Trust Settings- How to force Other authorization? When configuring the Mail Profile Server, there is no option to select other authorization than ACS. How can we change this?
Holly Huffman 6,212 on at

Like (1)

Report
Aquiring Token from ACS has failed.

Good morning, afternoon, or evening—depending on where you are in the world!
Hope you're doing well.

Thanks for the detailed context. You're encountering the error "Acquiring Token from ACS has failed" while configuring Dynamics 365 On-Premises to connect with Exchange Online. This is a known issue that can stem from several misconfigurations or outdated guidance.
Here’s a breakdown of what’s going on and how to resolve it:

Root Cause
The error typically occurs during the OAuth authentication handshake between Dynamics 365 On-Prem and Exchange Online. It often points to issues with:

Incorrect or expired certificates

Misconfigured application registration

Outdated PowerShell commands or parameters

Missing or misused claims-based authentication setup

Resolution Steps

Use Updated Microsoft Documentation
Refer to the official Microsoft guide for setting up server-based authentication between Dynamics 365 On-Prem and Exchange Online: Connect Exchange Online to Dynamics 365 On-Premises

Avoid Deprecated Commands
The Set-CrmRecord -AttributeList command mentioned in the community thread you referenced is outdated or incorrect. Instead, use Set-CrmRecord with the -Fields parameter or switch to Set-CrmEntity if you're using XrmTooling.

Validate Certificate Configuration
Ensure the certificate used for the application is:

Trusted by the Dynamics server

Not expired

Properly assigned in the application registration in Azure AD

Check ACS Trust Settings
If you're still using ACS (Access Control Service), consider migrating to Azure AD-based authentication, as ACS is deprecated and may not be supported in newer configurations.

PowerShell Compatibility
If you're using PowerShell 7+, note that some modules (like MSOnline or ExchangeOnlineManagement) may not be fully compatible. Try using PowerShell 5.1 for setup tasks.

Next Steps

Revisit your PowerShell scripts and replace deprecated parameters.

Follow the Microsoft documentation step-by-step, especially around certificate and app registration setup.

Note: I collaborated with AI to help craft this response and ensure it’s as accurate and helpful as possible.
Hope this helps some!