diff --git a/Dockerfile b/Dockerfile
index be60bfd..92ce546 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # Builder
-FROM node:current as builder
+FROM node:lts as builder
 
 WORKDIR /src
 
diff --git a/README.md b/README.md
index 60fc727..1c4483c 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,7 @@
 
 This project is built using [react-admin](https://marmelab.com/react-admin/).
 
+
 It needs at least Synapse v1.42.0 for all functions to work as expected!
 
 You get your server version with the request `/_synapse/admin/v1/server_version`.
diff --git a/src/components/RoomDirectory.js b/src/components/RoomDirectory.js
index d8d0469..0284e14 100644
--- a/src/components/RoomDirectory.js
+++ b/src/components/RoomDirectory.js
@@ -59,7 +59,7 @@ export const RoomDirectoryBulkDeleteButton = props => (
   <BulkDeleteButton
     {...props}
     label="resources.room_directory.action.erase"
-    undoable={false}
+    mutationMode="pessimistic"
     confirmTitle="resources.room_directory.action.title"
     confirmContent="resources.room_directory.action.content"
     resource="room_directory"
@@ -191,7 +191,7 @@ export const FilterableRoomDirectoryList = ({
       filters={<RoomDirectoryFilter />}
       perPage={100}
     >
-      <Datagrid>
+      <Datagrid rowClick={(id, basePath, record) => "/rooms/" + id + "/show"}>
         <AvatarField
           source="avatar_src"
           sortable={false}
diff --git a/src/components/ServerNotices.js b/src/components/ServerNotices.js
index 2a3e8bd..6b9b95c 100644
--- a/src/components/ServerNotices.js
+++ b/src/components/ServerNotices.js
@@ -24,7 +24,10 @@ const ServerNoticeDialog = ({ open, loading, onClose, onSend }) => {
 
   const ServerNoticeToolbar = props => (
     <Toolbar {...props}>
-      <SaveButton label="resources.servernotices.action.send" />
+      <SaveButton
+        label="resources.servernotices.action.send"
+        disabled={props.pristine}
+      />
       <Button label="ra.action.cancel" onClick={onClose}>
         <IconCancel />
       </Button>
diff --git a/src/components/rooms.js b/src/components/rooms.js
index d91db05..fa01c77 100644
--- a/src/components/rooms.js
+++ b/src/components/rooms.js
@@ -315,7 +315,7 @@ const RoomBulkActionButtons = props => (
       {...props}
       confirmTitle="resources.rooms.action.erase.title"
       confirmContent="resources.rooms.action.erase.content"
-      undoable={false}
+      mutationMode="pessimistic"
     />
   </Fragment>
 );
diff --git a/src/components/users.js b/src/components/users.js
index c954416..ff29fdf 100644
--- a/src/components/users.js
+++ b/src/components/users.js
@@ -36,7 +36,9 @@ import {
   BulkDeleteButton,
   DeleteButton,
   SaveButton,
+  maxLength,
   regex,
+  required,
   useTranslate,
   Pagination,
   CreateButton,
@@ -142,7 +144,7 @@ const UserBulkActionButtons = props => (
       {...props}
       label="resources.users.action.erase"
       confirmTitle="resources.users.helper.erase"
-      undoable={false}
+      mutationMode="pessimistic"
     />
   </Fragment>
 );
@@ -180,10 +182,16 @@ export const UserList = props => {
 };
 
 // https://matrix.org/docs/spec/appendices#user-identifiers
-const validateUser = regex(
-  /^@[a-z0-9._=\-/]+:.*/,
-  "synapseadmin.users.invalid_user_id"
-);
+// here only local part of user_id
+// maxLength = 255 - "@" - ":" - localStorage.getItem("home_server").length
+// localStorage.getItem("home_server").length is not valid here
+const validateUser = [
+  required(),
+  maxLength(253),
+  regex(/^[a-z0-9._=\-/]+$/, "synapseadmin.users.invalid_user_id"),
+];
+
+const validateAddress = [required(), maxLength(255)];
 
 export function generateRandomUser() {
   const homeserver = localStorage.getItem("home_server");
@@ -230,7 +238,7 @@ const UserEditToolbar = props => {
   const translate = useTranslate();
   return (
     <Toolbar {...props}>
-      <SaveButton submitOnEnter={true} />
+      <SaveButton submitOnEnter={true} disabled={props.pristine} />
       <DeleteButton
         label="resources.users.action.erase"
         confirmTitle={translate("resources.users.helper.erase", {
@@ -247,8 +255,12 @@ export const UserCreate = props => (
   <Create {...props}>
     <SimpleForm>
       <TextInput source="id" autoComplete="off" validate={validateUser} />
-      <TextInput source="displayname" />
-      <PasswordInput source="password" autoComplete="new-password" />
+      <TextInput source="displayname" validate={maxLength(256)} />
+      <PasswordInput
+        source="password"
+        autoComplete="new-password"
+        validate={maxLength(512)}
+      />
       <BooleanInput source="admin" />
       <ArrayInput source="threepids">
         <SimpleFormIterator>
@@ -258,8 +270,19 @@ export const UserCreate = props => (
               { id: "email", name: "resources.users.email" },
               { id: "msisdn", name: "resources.users.msisdn" },
             ]}
+            validate={required()}
+          />
+          <TextInput source="address" validate={validateAddress} />
+        </SimpleFormIterator>
+      </ArrayInput>
+      <ArrayInput source="external_ids" label="synapseadmin.users.tabs.sso">
+        <SimpleFormIterator>
+          <TextInput source="auth_provider" validate={required()} />
+          <TextInput
+            source="external_id"
+            label="resources.users.fields.id"
+            validate={required()}
           />
-          <TextInput source="address" />
         </SimpleFormIterator>
       </ArrayInput>
     </SimpleForm>
@@ -339,16 +362,16 @@ export const UserEdit = props => {
           icon={<AssignmentIndIcon />}
           path="sso"
         >
-          <ArrayField source="external_ids" label={false}>
-            <Datagrid style={{ width: "100%" }}>
-              <TextField source="auth_provider" sortable={false} />
-              <TextField
+          <ArrayInput source="external_ids" label={false}>
+            <SimpleFormIterator>
+              <TextInput source="auth_provider" validate={required()} />
+              <TextInput
                 source="external_id"
                 label="resources.users.fields.id"
-                sortable={false}
+                validate={required()}
               />
-            </Datagrid>
-          </ArrayField>
+            </SimpleFormIterator>
+          </ArrayInput>
         </FormTab>
 
         <FormTab
diff --git a/src/i18n/de.js b/src/i18n/de.js
index b3487a8..ed4470a 100644
--- a/src/i18n/de.js
+++ b/src/i18n/de.js
@@ -12,8 +12,7 @@ const de = {
       url_error: "Keine gültige Matrix Server URL",
     },
     users: {
-      invalid_user_id:
-        "Muss eine vollständige Matrix Benutzer-ID sein, z.B. @benutzer_id:homeserver",
+      invalid_user_id: "Lokaler Anteil der Matrix Benutzer-ID ohne Homeserver.",
       tabs: { sso: "SSO" },
     },
     rooms: {
diff --git a/src/i18n/en.js b/src/i18n/en.js
index f4a8260..7306a1d 100644
--- a/src/i18n/en.js
+++ b/src/i18n/en.js
@@ -12,8 +12,7 @@ const en = {
       url_error: "Not a valid Matrix server URL",
     },
     users: {
-      invalid_user_id:
-        "Must be a fully qualified Matrix user-id, e.g. @user_id:homeserver",
+      invalid_user_id: "Localpart of a Matrix user-id without homeserver.",
       tabs: { sso: "SSO" },
     },
     rooms: {
diff --git a/src/synapse/dataProvider.js b/src/synapse/dataProvider.js
index adf0a69..b80b075 100644
--- a/src/synapse/dataProvider.js
+++ b/src/synapse/dataProvider.js
@@ -41,7 +41,9 @@ const resourceMap = {
     data: "users",
     total: json => json.total,
     create: data => ({
-      endpoint: `/_synapse/admin/v2/users/${data.id}`,
+      endpoint: `/_synapse/admin/v2/users/@${data.id}:${localStorage.getItem(
+        "home_server"
+      )}`,
       body: data,
       method: "PUT",
     }),
diff --git a/yarn.lock b/yarn.lock
index 66c1d5b..532abd7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -7729,9 +7729,9 @@ minipass-pipeline@^1.2.2:
     minipass "^3.0.0"
 
 minipass@^3.0.0, minipass@^3.1.1:
-  version "3.1.3"
-  resolved "https://registry.yarnpkg.com/minipass/-/minipass-3.1.3.tgz#7d42ff1f39635482e15f9cdb53184deebd5815fd"
-  integrity sha512-Mgd2GdMVzY+x3IJ+oHnVM+KG3lA5c8tnabyJKmHSaG2kAGpudxuOf8ToDkhumF7UzME7DecbQE9uOZhNm7PuJg==
+  version "3.1.5"
+  resolved "https://registry.yarnpkg.com/minipass/-/minipass-3.1.5.tgz#71f6251b0a33a49c01b3cf97ff77eda030dff732"
+  integrity sha512-+8NzxD82XQoNKNrl1d/FSi+X8wAEWR+sbYAfIvub4Nz0d22plFG72CEVVaufV8PNf4qSslFTD8VMOxNVhHCjTw==
   dependencies:
     yallist "^4.0.0"
 
@@ -11077,9 +11077,9 @@ tapable@^1.0.0, tapable@^1.1.3:
   integrity sha512-4WK/bYZmj8xLr+HUCODHGF1ZFzsYffasLUgEiMBY4fgtltdO6B4WJtlSbPaDTLpYTcGVwM2qLnFTICEcNxs3kA==
 
 tar@^6.0.2:
-  version "6.1.8"
-  resolved "https://registry.yarnpkg.com/tar/-/tar-6.1.8.tgz#4fc50cfe56511c538ce15b71e05eebe66530cbd4"
-  integrity sha512-sb9b0cp855NbkMJcskdSYA7b11Q8JsX4qe4pyUAfHp+Y6jBjJeek2ZVlwEfWayshEIwlIzXx0Fain3QG9JPm2A==
+  version "6.1.11"
+  resolved "https://registry.yarnpkg.com/tar/-/tar-6.1.11.tgz#6760a38f003afa1b2ffd0ffe9e9abbd0eab3d621"
+  integrity sha512-an/KZQzQUkZCkuoAA64hM92X0Urb6VpRhAFllDzz44U2mcD5scmT3zBc4VgVpkugF580+DQn8eAFSyoQt0tznA==
   dependencies:
     chownr "^2.0.0"
     fs-minipass "^2.0.0"
@@ -11213,9 +11213,9 @@ tiny-warning@^1.0.0, tiny-warning@^1.0.2, tiny-warning@^1.0.3:
   integrity sha512-lBN9zLN/oAf68o3zNXYrdCt1kP8WsiGW8Oo2ka41b2IM5JL/S1CTyX1rW0mb/zSuJun0ZUrDxx4sqvYS2FWzPA==
 
 tmpl@1.0.x:
-  version "1.0.4"
-  resolved "https://registry.yarnpkg.com/tmpl/-/tmpl-1.0.4.tgz#23640dd7b42d00433911140820e5cf440e521dd1"
-  integrity sha1-I2QN17QtAEM5ERQIIOXPRA5SHdE=
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/tmpl/-/tmpl-1.0.5.tgz#8683e0b902bb9c20c4f726e3c0b69f36518c07cc"
+  integrity sha512-3f0uOEAQwIqGuWW2MVzYg8fV/QNnc/IpuJNG837rLuczAaLVHslWHZQj4IGiEl5Hs3kkbhwL9Ab7Hrsmuj+Smw==
 
 to-arraybuffer@^1.0.0:
   version "1.0.1"