diff --git a/src/i18n/locales/en/marketplace.json b/src/i18n/locales/en/marketplace.json
index 17ae20078a..b911cb8ec5 100644
--- a/src/i18n/locales/en/marketplace.json
+++ b/src/i18n/locales/en/marketplace.json
@@ -64,6 +64,7 @@
 		"installError": "Failed to install \"{{itemName}}\": {{errorMessage}}",
 		"removing": "Removing item: \"{{itemName}}\"",
 		"removeSuccess": "\"{{itemName}}\" removed successfully",
-		"removeError": "Failed to remove \"{{itemName}}\": {{errorMessage}}"
+		"removeError": "Failed to remove \"{{itemName}}\": {{errorMessage}}",
+		"notInstalledForTarget": "Mode not found"
 	}
 }
diff --git a/src/services/marketplace/MarketplaceManager.ts b/src/services/marketplace/MarketplaceManager.ts
index 704b930a21..72ac6b64da 100644
--- a/src/services/marketplace/MarketplaceManager.ts
+++ b/src/services/marketplace/MarketplaceManager.ts
@@ -4,7 +4,13 @@ import * as path from "path"
 import * as vscode from "vscode"
 import * as yaml from "yaml"
 
-import type { OrganizationSettings, MarketplaceItem, MarketplaceItemType, McpMarketplaceItem, ModeConfig } from "@roo-code/types"
+import type {
+	OrganizationSettings,
+	MarketplaceItem,
+	MarketplaceItemType,
+	McpMarketplaceItem,
+	ModeConfig,
+} from "@roo-code/types"
 import { customModesSettingsSchema } from "@roo-code/types"
 import { TelemetryService } from "@roo-code/telemetry"
 import { CloudService } from "@roo-code/cloud"
@@ -254,10 +260,7 @@ export class MarketplaceManager {
 	}
 
 	// Helper: parse YAML and collect installed mode metadata with proper typing
-	private collectInstalledModesFromYaml(
-		content: string,
-		out: Record<string, { type: string }>,
-	): void {
+	private collectInstalledModesFromYaml(content: string, out: Record<string, { type: string }>): void {
 		try {
 			const parsed = yaml.parse(content)
 			const result = customModesSettingsSchema.safeParse(parsed)
@@ -266,7 +269,7 @@ export class MarketplaceManager {
 			}
 			for (const mode of result.data.customModes) {
 				if (this.isMarketplaceInstalledMode(mode)) {
-					out[mode.marketplaceItemId!] = { type: "mode" }
+					out[mode.marketplaceItemId] = { type: "mode" }
 				}
 			}
 		} catch {
diff --git a/src/services/marketplace/SimpleInstaller.ts b/src/services/marketplace/SimpleInstaller.ts
index 960dcedc0b..ac53c14fb8 100644
--- a/src/services/marketplace/SimpleInstaller.ts
+++ b/src/services/marketplace/SimpleInstaller.ts
@@ -2,7 +2,7 @@ import * as vscode from "vscode"
 import * as path from "path"
 import * as fs from "fs/promises"
 import * as yaml from "yaml"
-import type { MarketplaceItem, MarketplaceItemType, InstallMarketplaceItemOptions, McpParameter, ModeConfig } from "@roo-code/types"
+import type { MarketplaceItem, McpParameter, ModeConfig } from "@roo-code/types"
 import { GlobalFileNames } from "../../shared/globalFileNames"
 import { ensureSettingsDirectoryExists } from "../../utils/globalContext"
 import type { CustomModesManager } from "../../core/config/CustomModesManager"
@@ -22,6 +22,7 @@ export class SimpleInstaller {
 
 	async installItem(item: MarketplaceItem, options: InstallOptions): Promise<{ filePath: string; line?: number }> {
 		const { target } = options
+		const itemType = item.type
 
 		switch (item.type) {
 			case "mode":
@@ -29,7 +30,7 @@ export class SimpleInstaller {
 			case "mcp":
 				return await this.installMcp(item, target, options)
 			default:
-				throw new Error("Unsupported item type")
+				throw new Error(`Unsupported item type: ${itemType}`)
 		}
 	}
 
@@ -293,6 +294,7 @@ export class SimpleInstaller {
 
 	async removeItem(item: MarketplaceItem, options: InstallOptions): Promise<void> {
 		const { target } = options
+		const itemType = item.type
 
 		switch (item.type) {
 			case "mode":
@@ -302,7 +304,7 @@ export class SimpleInstaller {
 				await this.removeMcp(item, target)
 				break
 			default:
-				throw new Error("Unsupported item type")
+				throw new Error(`Unsupported item type: ${itemType}`)
 		}
 	}
 
@@ -343,16 +345,12 @@ export class SimpleInstaller {
 		)
 
 		if (!candidate) {
-			throw new Error(t("common:customModes.errors.modeNotFound"))
+			const msg = t("marketplace:installation.notInstalledForTarget")
+			throw new Error(msg === "installation.notInstalledForTarget" ? "Mode not found" : msg)
 		}
 
 		// Delete only from the selected source to avoid unintended removals
-		if (typeof (this.customModesManager as any).deleteCustomModeForSource === "function") {
-			await (this.customModesManager as any).deleteCustomModeForSource(modeSlug, target, true)
-		} else {
-			// Scoped deletion not supported in this version
-			throw new Error("Scoped deletion is not supported in this version")
-		}
+		await this.customModesManager.deleteCustomModeForSource(modeSlug, target, true)
 	}
 
 	private async removeMcp(item: MarketplaceItem, target: "project" | "global"): Promise<void> {