diff --git a/backend/src/federation/client/1_0/AuthenticationClient.ts b/backend/src/federation/client/1_0/AuthenticationClient.ts
index 96e7f8a20..abc903778 100644
--- a/backend/src/federation/client/1_0/AuthenticationClient.ts
+++ b/backend/src/federation/client/1_0/AuthenticationClient.ts
@@ -44,7 +44,7 @@ export class AuthenticationClient {
       )
       return true
     } catch (err) {
-      logger.error('Authentication: error on openConnection', err)
+      logger.error('Authentication: error on openConnection: ', err)
     }
   }
 }
diff --git a/federation/src/graphql/api/1_0/util/authenticateCommunity.ts b/federation/src/graphql/api/1_0/util/authenticateCommunity.ts
index 24cd5768a..83a9d7987 100644
--- a/federation/src/graphql/api/1_0/util/authenticateCommunity.ts
+++ b/federation/src/graphql/api/1_0/util/authenticateCommunity.ts
@@ -40,7 +40,7 @@ export async function startOpenConnectionCallback(
       callbackArgs.oneTimeCode = oneTimeCode.toString()
       // TODO encrypt callbackArgs.url with requestedCom.publicKey and sign it with homeCom.privateKey
       callbackArgs.url = homeFedCom.endPoint.endsWith('/')
-        ? homeFedCom.endPoint
+        ? homeFedCom.endPoint + homeFedCom.apiVersion
         : homeFedCom.endPoint + '/' + homeFedCom.apiVersion
       logger.debug(`Authentication: start openConnectionCallback with args:`, callbackArgs)
       if (await client.openConnectionCallback(callbackArgs)) {