{"record":{"id":"7cced3da0c45428c","repo":"bevyengine/bevy","slug":"plugin-does-not-exist-in-group","errorCode":null,"errorMessage":"Plugin does not exist in group: {}.","messagePattern":"Plugin does not exist in group: (.+?)\\.","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"crates/bevy_app/src/plugin_group.rs","lineNumber":440,"sourceCode":"            );\n\n            self.order.push(plugin_id);\n        }\n\n        self\n    }\n\n    /// Adds a [`Plugin`] in this [`PluginGroupBuilder`] before the plugin of type `Target`.\n    ///\n    /// If the plugin was already the group, it is removed from its previous place.\n    ///\n    /// # Panics\n    ///\n    /// Panics if `Target` is not already in this [`PluginGroupBuilder`].\n    pub fn add_before<Target: Plugin>(self, plugin: impl Plugin) -> Self {\n        self.try_add_before_overwrite::<Target, _>(plugin)\n            .unwrap_or_else(|_| {\n                panic!(\n                    \"Plugin does not exist in group: {}.\",\n                    core::any::type_name::<Target>()\n                )\n            })\n    }\n\n    /// Adds a [`Plugin`] in this [`PluginGroupBuilder`] before the plugin of type `Target`.\n    ///\n    /// If the plugin was already in the group the add fails. If there isn't a plugin\n    /// of type `Target` in the group the plugin we're trying to insert is returned.\n    pub fn try_add_before<Target: Plugin, Insert: Plugin>(\n        self,\n        plugin: Insert,\n    ) -> Result<Self, (Self, Insert)> {\n        if self.contains::<Insert>() {\n            return Err((self, plugin));\n        }\n","sourceCodeStart":422,"sourceCodeEnd":458,"githubUrl":"https://github.com/bevyengine/bevy/blob/396ca727080776bd313bb892423b7d94e03b81b4/crates/bevy_app/src/plugin_group.rs#L422-L458","documentation":"Panics in PluginGroupBuilder::add_before when try_add_before_overwrite fails because the target plugin type Target is not present in the builder. The method can only reorder plugins that already exist in the group; the new plugin has no anchor to be placed before.","triggerScenarios":"Thrown at crates/bevy_app/src/plugin_group.rs:440 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Ensure the Target plugin type is in the group before calling add_before (add it or keep it from the default group)","Use plain add() if you do not need ordering relative to a target plugin","Verify the Target generic parameter names the plugin you intended"],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"396ca727080776bd313bb892423b7d94e03b81b4","analyzedAt":"2026-08-20T16:12:39.808Z","contentChangedAt":"2026-08-20T16:12:39.808Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}