---
title: "CLR Activation Debugging - Air Market"
description: "Your .NET Framework app starts up and something is off: it will not load, it grabs a version you did not expect, or a install-this-component dialog keeps popping up. This reads the activation logs th…"
canonical: "https://airmarket.ai/app/clr-activation-debugging"
---

[Air Market](/) / [Developer Tools](/category/devtools) / CLR Activation Debugging

Skill by [.NET Platform](/@dotnet)

# CLR Activation Debugging

When .NET picks the wrong runtime and nobody knows why

## What this does

Your .NET Framework app starts up and something is off: it will not load, it grabs a version you did not expect, or a install-this-component dialog keeps popping up. This reads the activation logs the runtime writes and tells you what happened at startup. Reach for it when the startup behaviour makes no sense.

### Top 3 things it does for you

- Work out which runtime version actually loaded
- Explain why a .NET 3.5 install prompt keeps appearing
- Track down failures when two runtime versions land in one process

## Information

**CLR Activation Debugging at a glance**

|  |  |
| --- | --- |
| Kind | Skill |
| Publisher | [.NET Platform](/@dotnet) |
| Category | [Developer Tools](/category/devtools) |
| Works with | Agent Skills - an open standard supported by 40+ agents |
| Size | 53 KB |
| Licence | MIT |
| Repository | [dotnet/skills](https://github.com/dotnet/skills/tree/9433a31e677da42032f1512b6c632ea06211f883/plugins/dotnet-diag/skills/clr-activation-debugging) |
| GitHub stars | 5,236 (as of Nov 2026) |
| Installs | 4,155, counted by skills.sh (Nov 2026) |

## Security report

**Verified.** AIR scanned this exact version of CLR Activation Debugging and flagged nothing. AIR's verdict: **safe**.

**What CLR Activation Debugging's check was run against**

|  |  |
| --- | --- |
| Commit | 9433a31e677da42032f1512b6c632ea06211f883 |
| Content hash | 11f590eca1a6078158c9daa89ed707f6de5a67c5328a7f0106dc30427f3b0329 |
| Files read | [Browse the files at this exact commit](https://github.com/dotnet/skills/blob/9433a31e677da42032f1512b6c632ea06211f883/plugins/dotnet-diag/skills/clr-activation-debugging/SKILL.md) |

A scan is named by the exact content it read, not by a version number. A different version is a different artifact, and nothing here applies to a version AIR has not scanned.

[Read the full security report for CLR Activation Debugging](/security/clr-activation-debugging)

## About CLR Activation Debugging

This helps you understand what .NET Framework does at startup, using the CLR activation logs produced by mscoree.dll. When the shim picks a runtime you did not expect, or fails to load one at all, the logs are where the answer is.

It also covers the odd cases around .NET 3.5 Feature-on-Demand: the dialog appearing when it should not, or not appearing when you expected it. And it covers processes that end up with both v2 and v4 loaded, which causes failures of its own.

Useful any time somebody is asking what is happening with .NET Framework activation.

## What's inside

- SKILL.md - instructions
- references/activation-flow.md - reference
- references/com-activation.md - reference
- references/log-format.md - reference

## Questions

### Is CLR Activation Debugging safe to install?

AIR scanned this exact version of CLR Activation Debugging and flagged nothing. AIR's verdict: safe. The verdict is named by the content that was read, at commit 9433a31e677d, so it cannot drift onto a version nobody scanned. The full report is at https://airmarket.ai/security/clr-activation-debugging.

### How do I install CLR Activation Debugging?

Open https://airmarket.ai/app/clr-activation-debugging on Air Market and use the install action: Air Market hands Claude a prompt naming this exact skill, and Claude sets it up. Source, pinned to the exact commit this listing describes: https://github.com/dotnet/skills/tree/9433a31e677da42032f1512b6c632ea06211f883/plugins/dotnet-diag/skills/clr-activation-debugging. Install from that link, not the branch.

## Related on Air Market

- [More Developer Tools listings](/category/devtools)
- [Everything by .NET Platform](/@dotnet)

---

Canonical URL: <https://airmarket.ai/app/clr-activation-debugging>