diff --git a/backend/src/config/index.ts b/backend/src/config/index.ts
index b94178157..0aed77583 100644
--- a/backend/src/config/index.ts
+++ b/backend/src/config/index.ts
@@ -128,8 +128,10 @@ if (
 
 const federation = {
   FEDERATION_BACKEND_SEND_ON_API: process.env.FEDERATION_BACKEND_SEND_ON_API ?? '1_0',
-  FEDERATION_VALIDATE_COMMUNITY_TIMER:
-    Number(process.env.FEDERATION_VALIDATE_COMMUNITY_TIMER) ?? 60000,
+  // ?? operator don't work here as expected
+  FEDERATION_VALIDATE_COMMUNITY_TIMER: Number(
+    process.env.FEDERATION_VALIDATE_COMMUNITY_TIMER ?? 60000,
+  ),
   FEDERATION_XCOM_SENDCOINS_ENABLED:
     process.env.FEDERATION_XCOM_SENDCOINS_ENABLED === 'true' ?? false,
   // default value for community-uuid is equal uuid of stage-3
diff --git a/backend/src/federation/validateCommunities.ts b/backend/src/federation/validateCommunities.ts
index f19d606bd..b76e22087 100644
--- a/backend/src/federation/validateCommunities.ts
+++ b/backend/src/federation/validateCommunities.ts
@@ -8,6 +8,7 @@ import { FederatedCommunityLoggingView } from '@logging/FederatedCommunityLoggin
 import { FederationClient as V1_0_FederationClient } from '@/federation/client/1_0/FederationClient'
 import { PublicCommunityInfo } from '@/federation/client/1_0/model/PublicCommunityInfo'
 import { FederationClientFactory } from '@/federation/client/FederationClientFactory'
+import { LogError } from '@/server/LogError'
 import { backendLogger as logger } from '@/server/logger'
 
 import { startCommunityAuthentication } from './authenticateCommunities'
@@ -15,6 +16,9 @@ import { PublicCommunityInfoLoggingView } from './client/1_0/logging/PublicCommu
 import { ApiVersionType } from './enum/apiVersionType'
 
 export async function startValidateCommunities(timerInterval: number): Promise<void> {
+  if (Number.isNaN(timerInterval) || timerInterval <= 0) {
+    throw new LogError('FEDERATION_VALIDATE_COMMUNITY_TIMER is not a positive number')
+  }
   logger.info(
     `Federation: startValidateCommunities loop with an interval of ${timerInterval} ms...`,
   )
diff --git a/deployment/hetzner_cloud/README.md b/deployment/hetzner_cloud/README.md
index d03ff0b46..d2cd66a35 100644
--- a/deployment/hetzner_cloud/README.md
+++ b/deployment/hetzner_cloud/README.md
@@ -1,7 +1,4 @@
 # Setup on Hetzner Cloud Server
-Suggested minimal Plan: CX41
-4x vCPU, 16 GB Ram, 160 GB Disk Space, 20.71 € per month (04.01.2024) 
-
 Suggested OS:
 Debian 12
 
@@ -15,6 +12,10 @@ ssh_authorized_keys:
   - ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAkLGbzbG7KIGfkssKJBkc/0EVAzQ/8vjvVHzNdxhK8J yourname
 ```
 
+I made a (german) video to show it to you:
+
+[![Video](https://img.youtube.com/vi/fORK3Bt3lPw/hqdefault.jpg)](https://www.youtube.com/watch?v=fORK3Bt3lPw)
+
 ## After Setup Cloud Server with cloudConfig.yaml
 ### setup your domain pointing on server ip address 
 ### login to your new server as root
@@ -99,16 +100,20 @@ nano .env
 # adjust values accordingly
 ```
 
-### Run `install.sh`
+### Run `install.sh` with branch name
 ***!!! Attention !!!***
 Don't use this script if you have custom config in /etc/nginx/conf.d, because this script
 will remove it and ln ../bare_metal/nginx/conf.d
 
 ```bash
 cd ~/gradido/deployment/hetzner_cloud
-sudo ./install.sh
+sudo ./install.sh release-2_2_0
 ```
 
+I made a (german) video to show it to you:
+
+[![Video](https://img.youtube.com/vi/9h-55Si6bMk/hqdefault.jpg)](https://www.youtube.com/watch?v=9h-55Si6bMk)
+
 ### Make yourself admin
 - Create an account on your new gradido instance
 - Click the link in the activation email
@@ -122,3 +127,6 @@ sudo mysql -D gradido_community -e "insert into user_roles(user_id, role) values
 - login with you newly created user
 - if you has a link to `Admin Area` it worked and you are admin
 
+I made a (german) video to show it to you:
+
+[![Video](https://img.youtube.com/vi/xVQ5t4MnLrE/hqdefault.jpg)](https://www.youtube.com/watch?v=xVQ5t4MnLrE)