claude-code - 💡(How to fix) Fix Plugin validation failed on save — cannot overwrite existing personal plugin in account-scoped marketplace (HTTP 400 plugin_validation) [1 comments, 1 participants]

Actual result: "Plugin validation failed" error. Plugin is not saved. The error originates from a server-side HTTP 400 response with error code plugin_validation during the upload to the account-scoped marketplace. The actual server error message is not surfaced in the UI or in any log file. There is no option in the UI to delete a plugin from the personal marketplace — only local uninstall is available, which does not reset the server-side state.

Error Messages/Logs

TL;DR

The "Plugin validation failed" error when saving changes to a personal plugin in Cowork mode may be resolved by investigating the server-side validation rules or resetting the server-side state of the plugin.

Guidance

• Investigate the server-side validation rules for plugins in the account-scoped marketplace to identify potential issues with the plugin's configuration or content.
• Try uninstalling the plugin locally and then reinstalling it to see if the issue persists, which may help determine if the problem is with the plugin itself or the server-side state.
• Consider reaching out to the development team or support for assistance in resetting the server-side state of the plugin, as there is no option in the UI to delete a plugin from the personal marketplace.
• Review the changes made to the plugin files to ensure they comply with the expected format and content requirements.
• Check if any recent updates or changes to the Claude Code or Cowork mode may have introduced new validation rules or requirements for plugins.

Notes

The exact cause of the "Plugin validation failed" error is unclear due to the lack of detailed error messages or logs. The issue may be specific to the configuration or content of the plugin, or it could be related to a regression introduced in a recent version of Claude Code.

Recommendation

Apply workaround: Given the uncertainty around the cause and the lack of a clear fix, attempting to reset the server-side state of the plugin or seeking assistance from the development team may be the most viable option for resolving the issue.