Shut down other profilers, performance monitors, or secondary Visual Studio instances debugging the same process.
await diagnosticHubSession.StartCollectionAsync(targetProcessId);
From the Visual Studio Installer → select More → Repair . This restores missing or corrupted Diagnostic Hub components.
catch (DiagnosticsCollectionStartFailedHubException ex)
| Aspect | Detail | |--------|--------| | Type | Developer-environment exception, not production code | | Primary source | Visual Studio Diagnostic Tools | | Meaning | Failed to begin collecting performance/debug data from a target process | | Most common fix | Run VS as admin, close other profilers, repair VS | | Inner exception significance | High – reveals actual system-level failure | This exception is a diagnostic failure of a diagnostic tool—an ironic but informative error that typically points to environment or permission issues rather than a bug in your application code.
Common failure scenarios include: