Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problemsTrace the failure from the command or interface you used, through marketplace discovery and installation, to session loading and the plugin component that is failing. A plugin can be installed but not active in the current session, or it can load successfully while a skill, hook, or MCP server fails on its own.
First, confirm where the failure happens
Claude Code has different plugin workflows depending on whether you are using its interactive terminal, an IDE, Claude Desktop, or a cloud session. In an interactive terminal session, /plugin is a Claude Code command. If you type it at a Bash, Zsh, or PowerShell prompt, your shell will try to interpret it instead. Use claude plugin ... commands from the shell, or start Claude Code and enter /plugin in the interactive session.
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Before changing anything, record the exact error and where it appeared: the shell, terminal session, IDE or Desktop interface, plugin browser, or a component’s output. In the interactive plugin interface, check the Errors tab. That information helps distinguish a command-surface problem from a marketplace, installation, or runtime failure. The official troubleshooting guide covers plugin errors; the CLI reference documents command-line usage.
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Locate the failure stage
Work down this sequence rather than reinstalling immediately. Each stage has different evidence and a different likely fix.
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| Stage | What may be failing | Useful checks |
|---|---|---|
| Command or interface | The plugin command is being entered in the wrong place, or the expected surface does not support the same workflow. | Confirm whether you are in a shell, an interactive terminal session, an IDE or Desktop, or a cloud session; capture the exact error. |
| Marketplace lookup | The marketplace is not registered, its source is unreachable, or its local catalog is stale. | Check configured marketplaces, source spelling and access; refresh the marketplace if its catalog may be out of date. |
| Validation or installation | The plugin structure, marketplace entry, or relative source path is invalid. | Run claude plugin validate <path> and inspect the install error and marketplace entry. |
| Local state or session activation | The plugin is not enabled, is unavailable in the current scope, or has not loaded into this session. | Run claude plugin list and claude plugin details <name>; verify the applicable settings and session. |
| Component runtime | A skill, command, agent, hook, or MCP server fails independently after the plugin is installed. | Use the component inventory and the specific startup, invocation, hook, or connection error to isolate it. |
| Network or organization policy | A host, proxy, certificate, allowlist, or managed installation rule blocks discovery or execution. | Check debug information, /status where available, network requirements, and relevant administrator-managed settings. |
The plugin loading reference explains the relationship between enabled state, local plugin files, and session loading.
If Claude Code cannot find the marketplace or plugin
A marketplace is a catalog and source; it is not the same thing as a plugin installed on your machine. Check the exact marketplace name and source, and confirm that the repository, URL, or local path is available to the environment where Claude Code is running.
- In an interactive terminal session, the official marketplace is normally registered the first time the session starts. A failed attempt, a policy restriction, or an environment variable that disables automatic installation can prevent this.
- The CLI plugin commands do not register the official marketplace automatically. In the interactive session, add it with
/plugin marketplace add anthropics/claude-plugins-official. - If the plugin may have been added after the marketplace catalog was cached, refresh that marketplace and try again.
- For a private Git repository, make sure Git access works without an interactive credential prompt. If cloning fails, verify the repository and permissions, then check Git credentials, SSH host trust, Git availability, and clone timeout.
Do not assume a marketplace refresh succeeded just because a local catalog is present: an offline refresh can leave cached marketplace information stale. See the official plugin troubleshooting documentation for marketplace and source diagnostics.
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Run claude plugin validate <path> against the plugin or marketplace. Validation can find malformed JSON, missing required fields, and structural problems. A successful validation does not guarantee that installation can resolve every source path, so inspect the marketplace entry and the exact installation error as well.
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- For a local plugin source in a marketplace, the path is relative to the marketplace root: the directory containing
.claude-plugin/marketplace.json. Check that the target directory really exists at that relative location. - Compare the marketplace entry’s
namewith the plugin manifest’sname. The entry name is used as the installation identifier; component names come from the plugin manifest. - For a published plugin, do not change its manifest
nameto fix a display or discovery problem. The official plugin directory warns: “Once a plugin has been published, itsnamemust not change — users have it installed under that slug, and renaming it breaks their install with aplugin-not-founderror.”
The Plugins overview and troubleshooting guide describe plugin structure and common installation failures.
If it is installed but does not load in this session
Installation, enabled state, and session loading are separate checks. Run claude plugin list to inspect installed and enabled status, then claude plugin details <name> to see the plugin’s component inventory. Confirm that it is enabled in the applicable settings, that its files are present under ~/.claude/plugins/, and that the current session has loaded it.
Plugins load at session startup; if you installed or updated one while Claude Code was already running, use the plugin reload command documented for your current Claude Code version, or restart the session, then check the component inventory again. Avoid relying on a command name from an older guide if the current documentation for your installed version differs.
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Check installation scope and session type before reinstalling:
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- User scope: applies across projects for that user.
- Project scope: is represented in the repository’s
.claude/settings.json. - Local scope: applies to the user in that repository.
- Cloud sessions: do not load plugins from local settings.
A plugin installed or enabled in one scope or environment may therefore be absent from another. The loading reference describes the loader’s state requirements and scope behavior.
If only one plugin component fails
A plugin is installed and loaded as a unit, but its components have distinct runtime requirements. Use claude plugin details <name> to confirm which components are present, then troubleshoot the failing component rather than treating every symptom as a failed installation.
Skills and commands
If a skill or command is missing, check its directory placement, any manifest or custom paths, and—where applicable—the skill’s frontmatter. If the skill appears in the inventory but is not selected, discovery and invocation are separate issues: check whether the task actually matches the skill description rather than assuming it failed to load.
Agents
Use the component inventory to verify that the expected agent is packaged with the plugin. If it is listed but does not behave as expected, capture the specific invocation or runtime error; a successful plugin install alone does not establish that the agent ran successfully.
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Hooks
For a hook that does not load or fire, inspect its configuration and the specific hook error. Check that the configured command exists, is executable in the user’s environment, and has the permissions and environment variables it needs. A hook may load but fail when its event occurs, or block the operation it guards.
MCP servers
For an MCP server, inspect .mcp.json, the configured transport and command, startup errors, credentials, and connectivity. Separate an invalid server configuration from a server that fails to start or never connects. If it works under --plugin-dir but fails after installation, compare the plugin package path and the installed server’s runtime configuration; that contrast can distinguish a packaging-path issue from a server connectivity or startup problem.
The official troubleshooting guide organizes MCP failures by configuration, startup, connection, and plugin-directory behavior. Do not treat installation success as proof that a hook or server has run correctly.
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If downloads or connections fail
Plugin discovery and execution can depend on different network hosts. Anthropic’s current network guidance names github.com for Git-hosted marketplaces and plugins, downloads.claude.ai for plugin executable downloads, and registry.npmjs.org for npm plugin installs and dependencies. Allowlist only the hosts required by the source and component types you actually use; a Git marketplace, executable download, and npm dependency do not necessarily share the same network requirements.
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On a managed network, verify the configured HTTP(S) proxy, TLS trust store, and certificate paths. Use Claude Code debug output and /status where available to confirm which configuration loaded. A proxy URL or certificate authority error should be addressed before diagnosing the failure as a malformed plugin. See Anthropic’s enterprise network configuration.
If the error points to organization policy
Errors mentioning policy, blocked sources, or disabled sideloading may indicate a managed control rather than a broken plugin. Ask the administrator to check marketplace source allowlists or blocks, plugin installation policy, sideload settings, and session-only loading restrictions. Local settings cannot override every organization-managed restriction. The relevant controls are described in the plugin documentation and troubleshooting guide.
What to include when escalating a persistent failure
Share a concise diagnostic record with your administrator or plugin maintainer instead of only reporting that “the plugin does not work.” Include:
- The Claude Code surface and session type where the problem occurs.
- The exact error text and the stage where it appears.
- The marketplace source and plugin identifier, without exposing credentials.
- Output from
claude plugin list,claude plugin details <name>, andclaude plugin validate <path>when relevant. - Whether the issue is limited to a component such as a hook or MCP server, and any associated startup or connection error.
- Relevant debug or
/statusdetails for proxy, certificate, or policy issues, with secrets removed.
This evidence makes it possible to distinguish an unavailable source from a bad package, a stale session, a component runtime failure, or an administrative restriction without conflating them.
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