diff --git a/app/controllers/client_api/users/invitations_controller.rb b/app/controllers/client_api/users/invitations_controller.rb
index 87789769e..7765cf609 100644
--- a/app/controllers/client_api/users/invitations_controller.rb
+++ b/app/controllers/client_api/users/invitations_controller.rb
@@ -27,7 +27,14 @@ module ClientApi
 
       def check_invite_users_permission
         @team = Team.find_by_id(params[:team_id])
-        render_403 if @team && !is_admin_of_team(@team)
+        if @team && !is_admin_of_team(@team)
+          respond_to do |format|
+            format.json do
+              render json: t('client_api.invite_users.permission_error'),
+                     status: 422
+            end
+          end
+        end
       end
     end
   end
diff --git a/app/javascript/src/components/InviteUsersModal/index.jsx b/app/javascript/src/components/InviteUsersModal/index.jsx
index 8d702cfa2..a6a82a0d2 100644
--- a/app/javascript/src/components/InviteUsersModal/index.jsx
+++ b/app/javascript/src/components/InviteUsersModal/index.jsx
@@ -55,10 +55,15 @@ class InviteUsersModal extends Component {
         team_id: this.props.team.id
       })
       .then(({ data }) => {
-        this.setState({ inviteResults: data });
-        this.setState({ showInviteUsersResults: true });
+        this.setState({ inviteResults: data, showInviteUsersResults: true});
       })
-      .catch(error => {});
+      .catch(error => {
+        console.log("Invite As Error: ", error);
+        if (error.response) {
+          console.log("Error message:", error.response.data);
+          // TO DO: put this error in flash msg
+        }
+      });
   }
 
   render() {
diff --git a/app/javascript/src/config/locales/messages.js b/app/javascript/src/config/locales/messages.js
index b1f64bd33..07c3295eb 100644
--- a/app/javascript/src/config/locales/messages.js
+++ b/app/javascript/src/config/locales/messages.js
@@ -21,6 +21,43 @@ export default {
       notifications_label: "Notifications",
       info_label: "Info"
     },
+    invite_users: {
+      modal_title: "Invite users to team {team}",
+      input_text: "Invite more people to team {team} and start using sciNote.",
+      input_help:
+        "Input one or multiple emails, confirm each email with ENTER key.",
+      dropdown_button: {
+        invite: "Invite user/s",
+        guest: "as Guest/s",
+        normal_user: "as Normal user/s",
+        admin: "as Administrator/s"
+      },
+      results_title: "Invitation results:",
+      roles: {
+        guest: "Guest",
+        normal_user: "Normal user",
+        admin: "Administrator"
+      },
+      results_msg: {
+        user_exists: "User is already a member of sciNote.",
+        user_exists_unconfirmed:
+          "User is already a member of sciNote but is not confirmed yet.",
+        user_exists_and_in_team_unconfirmed:
+          "User is already a member of sciNote and team {team} as {role} but is not confirmed yet.",
+        user_exists_invited_to_team_unconfirmed:
+          "User is already a member of sciNote but is not confirmed yet - successfully invited to team {team} as {role}.",
+        user_exists_and_in_team:
+          "User is already a member of sciNote and team {team} as {role}.",
+        user_exists_invited_to_team:
+          "User was already a member of sciNote - successfully invited to team {team} as {role}.",
+        user_created: "User succesfully invited to sciNote.",
+        user_created_invited_to_team:
+          "User successfully invited to sciNote and team {team} as {role}.",
+        user_invalid: "Invalid email.",
+        too_many_emails:
+          "Only invited first {nr} emails. To invite more users, fill in another invitation form."
+      }
+    },
     settings_page: {
       all_teams: "All teams",
       in_team: "You are member of {num} team",
@@ -145,43 +182,6 @@ export default {
       greeting: "Hi, {name}",
       settings: "Settings",
       log_out: "Log out"
-    },
-    invite_users: {
-      modal_title: "Invite users to team {team}",
-      input_text: "Invite more people to team {team} and start using sciNote.",
-      input_help:
-        "Input one or multiple emails, confirm each email with ENTER key.",
-      dropdown_button: {
-        invite: "Invite user/s",
-        guest: "as Guest/s",
-        normal_user: "as Normal user/s",
-        admin: "as Administrator/s"
-      },
-      results_title: "Invitation results:",
-      roles: {
-        guest: "Guest",
-        normal_user: "Normal user",
-        admin: "Administrator"
-      },
-      results_msg: {
-        user_exists: "User is already a member of sciNote.",
-        user_exists_unconfirmed:
-          "User is already a member of sciNote but is not confirmed yet.",
-        user_exists_and_in_team_unconfirmed:
-          "User is already a member of sciNote and team {team} as {role} but is not confirmed yet.",
-        user_exists_invited_to_team_unconfirmed:
-          "User is already a member of sciNote but is not confirmed yet - successfully invited to team {team} as {role}.",
-        user_exists_and_in_team:
-          "User is already a member of sciNote and team {team} as {role}.",
-        user_exists_invited_to_team:
-          "User was already a member of sciNote - successfully invited to team {team} as {role}.",
-        user_created: "User succesfully invited to sciNote.",
-        user_created_invited_to_team:
-          "User successfully invited to sciNote and team {team} as {role}.",
-        user_invalid: "Invalid email.",
-        too_many_emails:
-          "Only invited first {nr} emails. To invite more users, fill in another invitation form."
-      }
     }
   }
 };
diff --git a/app/services/client_api/invitations_service.rb b/app/services/client_api/invitations_service.rb
index 4abb0e04f..a605b55f0 100644
--- a/app/services/client_api/invitations_service.rb
+++ b/app/services/client_api/invitations_service.rb
@@ -34,14 +34,8 @@ module ClientApi
 
         # Check if user already exists
         user = User.find_by_email(email) if User.exists?(email: email)
-
-        result = if user.blank?
-                   # User does not exist
-                   handle_new_user(result, email, user)
-                 else
-                   # User exists
-                   handle_existing_user(result, user)
-                 end
+        # Handle user invitation
+        result = handle_user(result, email, user)
         invite_results << result
       end
       invite_results
@@ -49,6 +43,11 @@ module ClientApi
 
     private
 
+    def handle_user(result, email, user)
+      return handle_new_user(result, email, user) if user.blank?
+      handle_existing_user(result, user)
+    end
+
     def handle_new_user(result, email, user)
       password = generate_user_password
       # Validate the user data
@@ -151,7 +150,7 @@ module ClientApi
         message: sanitize_input(message)
       )
 
-      if target_user.assignments_notification
+      if target_user.settings[:notifications][:assignments]
         UserNotification.create(notification: notification, user: target_user)
       end
     end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index c266d562c..e5112418b 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -1825,3 +1825,5 @@ en:
     user_teams:
       leave_team_error: "An error occured."
       leave_flash: "Successfuly left team %{team}."
+    invite_users:
+      permission_error: "You don't have permission to invite additional users to team. Contact its administrator/s."