diff --git a/src/azure/apim/ApimService.ts b/src/azure/apim/ApimService.ts
index 7967a8f..e62482b 100644
--- a/src/azure/apim/ApimService.ts
+++ b/src/azure/apim/ApimService.ts
@@ -6,6 +6,7 @@
 import { HttpOperationResponse, ServiceClient } from "@azure/ms-rest-js";
 import { TokenCredentialsBase } from "@azure/ms-rest-nodeauth";
 import { createGenericClient } from "vscode-azureextensionui";
+import { localize } from "../../localize";
 import { IApimServiceContract, IAuthorizationAccessPolicyContract, IAuthorizationAccessPolicyPropertiesContract, IAuthorizationContract, IAuthorizationLoginLinkRequest, IAuthorizationLoginLinkResponse, IAuthorizationPropertiesContract, IAuthorizationProviderContract, IAuthorizationProviderPropertiesContract, IGatewayApiContract, IGatewayContract, IMasterSubscription, ITokenStoreIdentityProviderContract } from "./contracts";
 
 export class ApimService {
@@ -88,6 +89,9 @@ export class ApimService {
             method: "GET",
             url: `${this.baseUrl}/subscriptions/master?api-version=${this.apiVersion}`
         });
+        if (result.status !== 200 || !result.parsedBody) {
+            throw new Error(localize("getSubscriptionMasterkeyError", `Failed to get master subscription at ${result.request.url}'. Status code: ${result.status}`));
+        }
         // tslint:disable-next-line: no-unsafe-any
         return result.parsedBody;
     }
@@ -278,6 +282,9 @@ export class ApimService {
     }
 
     private genSiteUrl(endPointUrl: string, subscriptionId: string, resourceGroup: string, serviceName: string): string {
+        if (endPointUrl.endsWith('/')) {
+            endPointUrl = endPointUrl.slice(0, -1);
+        }
         return `${endPointUrl}/subscriptions/${subscriptionId}/resourceGroups/${resourceGroup}/providers/Microsoft.ApiManagement/service/${serviceName}`;
     }
 }
diff --git a/src/debugger/debuggerConnection.ts b/src/debugger/debuggerConnection.ts
index fc27848..859699c 100644
--- a/src/debugger/debuggerConnection.ts
+++ b/src/debugger/debuggerConnection.ts
@@ -45,7 +45,7 @@ export class DebuggerConnection extends EventEmitter {
 				.on('error', e => {
 					if (this.connection == null || this.connection === connection) {
 						this.connection = null;
-						this.sendEvent('end', localize("", `Can't connect to gateway: ${e.message}.`));
+						this.sendEvent('end', localize("", `Can't connect to gateway at ${address}: ${e.message}.`));
 					}
 					reject();
 				})