clr-activation-debugging SKILL.md skillA
clr-activation-debugging from dotnet/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add dotnet/skills/clr-activation-debugging@git:20260831.5854dfdPins git:20260831.5854dfd in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- dotnet/skills
- Path
plugins/dotnet-diag/skills/clr-activation-debugging/SKILL.md- Versions recorded
- 4
- Latest version
- git:20260831.5854dfd, committed Aug 31, 2026
- First version recorded
- Mar 7, 2026
- Size
- 20,858 bytes
- Repository stars
- 5,836
- License
- MIT
Diagnoses .NET Framework CLR activation issues using CLR activation logs (CLRLoad logs) produced by mscoree.dll. Use when: the shim picks the wrong runtime, fails to load any runtime, shows unexpected .NET 3.5 Feature-on-Demand (FOD) dialogs, unexpectedly does NOT show FOD dialogs, loads both v2 and v4 into the same process causing failures, or any time someone is wondering "what is happening with .NET Framework activation?".
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# CLR Activation Debugging
Diagnose .NET Framework runtime activation issues by analyzing CLR activation logs (CLRLoad logs) produced by the shim (mscoree.dll). These logs record every decision the shim makes when selecting and loading a CLR version.
## When to Use
- A process fails to load the CLR at all ("Unable to find a version of the runtime to use")
- The shim picks the wrong CLR version (e.g., v2.0 instead of v4.0)
- Unexpected .NET 3.5 Feature-on-Demand (FOD) install dialogs appear
- FOD dialogs are expected but do NOT appear
- Both CLR v2 and CLR v4 load into the same process, causing failures
- A COM object fails to activate because the shim can't resolve the runtime
- Legacy hosting APIs (CorBindToRuntime) bind to an unexpected version
## When Not to Use
- **Modern .NET (CoreCLR / .NET 5+)** — this skill covers .NET Framework only (the mscoree.dll shim)
- **Assembly binding failures** — use Fusion logs (fuslogvw.exe), not CLR activation logs
- **Runtime crashes after the CLR has loaded** — activation succeeded; the problem is elsewhere
## Background
### The Shim Architecture
The .NET Framework shim has two layers:
…Read the whole file at its exact version.
How to install
mdr add dotnet/skills/clr-activation-debugging@sha256:de030774c23c61b3The line at the top of this page pins the label git:20260831.5854dfd, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_4445fq4p63fzwowt)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 4 versions of this file, between Mar 7, 2026 and Aug 31, 2026, about one every 59 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260831.5854dfd latest | 2026-08-31 | 5854dfd | 20,858 B | A | view · diff |
| git:20260825.c3cd3f7 | 2026-08-25 | c3cd3f7 | 20,696 B | A | view · diff |
| git:20260421.05aeb65 | 2026-04-21 | 05aeb65 | 20,295 B | A | view · diff |
| git:20260307.042a9d2 | 2026-03-07 | 042a9d2 | 20,282 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (20858 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
dotnet/skills · 5,836 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_4445fq4p63fzwowt GET https://markdownregistry.com/api/v1/resolve?ref=dotnet/skills/clr-activation-debugging GET https://markdownregistry.com/api/v1/blob/de030774c23c61b3297e82af68e1b15e37e2ad8df4028a54975b2a5af3183762
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.