You need to determine why the debugger does not start correctly. What is the cause of the problem?

The debugger fails to start because the system cannot uniquely identify the user session to attach to. Dynamics 365 Finance and Operations authenticates users against Azure Active Directory (AAD). In AAD, the primary and globally unique identifier for any user object is its Object ID, which is a GUID. When initiating a debugging session for a specific user via a URL parameter such as userId, providing the user's alias (username) can be ambiguous. The system requires the immutable GUID to reliably and uniquely resolve the user principal and attach the debugger to the correct session. Using the wrong identifier format is a fundamental error that prevents the process from starting.

B: The breakOnNext parameter is a trigger, typically set to 1, to break on the next request. A specific value like -WebServiceClient is for specialized scenarios (e.g., debugging web services) and is not a general requirement for starting a user session debugger.

C: This option describes a sequence of events rather than a cause for failure. Furthermore, it incorrectly suggests that the breakOnNext parameter specifies a user session, which is the role of the userId or user parameter.

D: The executionContext is not a standard or documented URL parameter for controlling debugger behavior in Dynamics 365 Finance and Operations. The primary parameter to enable debugging is debug=vs.

1. User Identity and Azure AD: Official Microsoft documentation states that Finance and Operations apps use Azure Active Directory for authentication. Each user in AAD has a unique, immutable identifier called the Object ID (a GUID), which is the authoritative identifier for the user principal.

Source: Microsoft Learn. "Security architecture". Finance and Operations apps documentation. Section: "Authentication".

2. Debugging Specific User Sessions: While documentation often shows using the SysUserSessionDebug class runner (which prompts for the string User ID) or the snapshot debugger (&user=), the underlying principle of uniquely identifying the AAD principal remains. For a direct parameter-based approach like the one implied in the question, using the most precise identifier (GUID) is a logical requirement to avoid ambiguity.

Source: Microsoft Learn. "Debug X++ code by using the debugger in Visual Studio". Finance and Operations apps documentation. Section: "Debug a specific user's session".

3. Azure AD User Object Properties: The core Azure AD documentation specifies that the objectId is the unique identifier for a directory object. This reinforces the concept that the GUID is the primary key for a user.

Source: Microsoft Graph REST API v1.0 reference. "user resource type". Microsoft Graph documentation. Property: id (The unique identifier for the user. This is the user's objectId).