What you need to know
Why does the default snapshot threshold of one still require an exception to occur twice?
Potentially affected
Application Insights Snapshot Debugger for supported .NET server applications; desktop clients such as WPF, Windows Forms and UWP are excluded.
DSE recommendation
Test the exception's collection-plan lifecycle with controlled repetitions instead of treating the first missing snapshot as a broken uploader.
Source facts
Snapshot Debugger counts exceptions by problem ID and adds the ID to a collection plan when the threshold is reached. With the default ThresholdForSnapshotting value of one, the same exception must occur twice before a snapshot is created. Collection also defaults to one snapshot per ten minutes, and the uploader is limited to fifty per day. WPF, Windows Forms and UWP clients are unsupported. Microsoft Learn.
Applicability
This concerns supported .NET server applications with Snapshot Debugger enabled. Microsoft warns that snapshots can contain sensitive variable and parameter values; use safe test data and appropriately controlled access. Microsoft Learn.
DSE recommendation
Test the exception’s collection-plan lifecycle with controlled repetitions instead of treating the first missing snapshot as a broken uploader. Record the configured threshold and rate limits before the test. Choose one identifiable, safe exception scenario and keep its repetitions distinct from unrelated exceptions. Do not raise production capture limits simply to make an initial test look successful.
Verification
Compare the exception observations, elapsed time and snapshot availability with the configured collection behavior. Confirm that the test did not exceed an applicable capture or upload limit before escalating a missing artifact. If capture still fails under the expected conditions, preserve the settings and sanitized event sequence for focused troubleshooting. Report the actual observations rather than claiming that every exception receives a snapshot or that one successful capture proves complete diagnostic coverage.
Official references
Microsoft Learn: Snapshot Debugger process. Source reviewed September 9, 2026.
Review the official source
Snapshot Debugger for .NET Exception Debugging - Azure Monitor | Microsoft Learn · Verified September 9, 2026
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