---
title: "Release notes for Application Observability plugin 1.66 | Grafana Cloud documentation"
description: "Release notes for Application Observability plugin 1.66"
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

# Release notes for Application Observability plugin 1.66

## 1.66.0

Released on 2025-11-10.

- Activating Tempo metrics generation now uses native histograms by default
- Add support for .NET 9 garbage collection runtime metrics
- Fixed an issue where Filter by and Group by attribute updates weren’t saved when using the Otel collector with Tempo metrics generation
- Fixed service overview tabs breaking when entity names contained unsupported characters

## 1.66.2

Released on 2025-11-14.

- Fix: Make sure that Group by queries use the selected metrics datasource