Changes in YourKit .NET Profiler 2025.9

• .NET support
• Windows support
• Security
• User interface
• Thread profiling
• Object allocation profiling
• IDE integration
• Profiler API
• Triggers
• Miscellaneous

.NET support

• feature .NET 10 is supported.
• fix Fixed an issue where thread names were missing when attaching the profiler to a running .NET application.

Windows support

• feature The uninstaller is now digitally signed.

Security

• improvement The profiler agent now rejects cross-site HTTP requests with the header Sec-Fetch-Site: cross-site. This is not a vulnerability by itself, but blocking such requests improves overall security. Cross-site requests can originate only from a web browser executing specially crafted web pages that send API requests (via JavaScript) to the YourKit agent running on localhost.

User interface

• improvement Improved detection of insufficient native memory during dominator calculation. The profiler now provides more detailed workaround suggestions in such cases.
• fix Fixed an issue where the first selected row in a table could change after the table was updated.

Thread profiling

• improvement Improved the behavior of the Show idle states option. When unchecked, only Runnable states are now displayed. Previously, the profiler used CPU time consumption in the sample to determine idleness, which could cause threads in Waiting state to appear as non-idle.

  

Object allocation profiling

• We replaced the record every N-th object and record objects larger than parameters of allocation profiling with a single parameter, sampling interval. Now the profiler records an object allocation whenever a thread allocates the next N bytes (sampling interval).

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IDE integration

• fix Fixed an issue in the JetBrains Rider plugin that caused SlowOperations.assertSlowOperationsAreAllowed warnings.
• fix Fixed an issue in the JetBrains Rider plugin that caused StartupManagerImpl - Migrate to ProjectActivity warnings.
• caveat Support for Visual Studio 2017 and 2019 has been dropped. The minimum supported version is now Visual Studio 2022.
• caveat The minimum supported JetBrains Rider version is now 2023.1.

Profiler API

• fix HTTP API requests are now validated by method. Only POST is accepted, as documented; GET and OPTIONS requests are rejected with 405 Method Not Allowed.
• caveat The sizeLimit and recordEach properties of AllocationProfilingSettings were replaced with interval property.
• caveat In the HTTP endpoint startAllocationProfiling, the options sizeLimit and recordEach were replaced with a single option interval.

Triggers

• caveat Triggers can now write or modify files only within the sandbox directory ~/.ynp/triggers_out. The directory can be changed using the triggers_out_dir agent startup option.

Miscellaneous

• caveat Agent option sampling is replaced with cpu=sampling.
• caveat Agent option tracing is replaced with cpu=tracing.