Steps to reproduce:

1. Create a host group (hostgroup01) and a host (host01) assigned to it.
2. Create a user group (usergroup01) with read-only access to that host group, and a user (user01) in it.
3. Create a map (submap01) containing host01 and Zabbix server.
   
   
4. Create another map (map01) including submap01.
   

Result:
The message "System error occurred. Please contact Zabbix administrator." will be displayed.

• 7.0.18
  
• 7.0.18 Debug Mode
  
  WebInterface DebugMode

  Undefined array key 10084 [zabbix.php:17 → require_once() → ZBase->run() → ZBase->processRequest() → ZBase->processResponseFinal() → CView->getOutput() → include() → CScreenMap->get() → CMapHelper::get() → CMapHelper::resolveMapState() → getSelementsInfo() in include/maps.inc.php:770]
  Trying to access array offset on value of type null [zabbix.php:17 → require_once() → ZBase->run() → ZBase->processRequest() → ZBase->processResponseFinal() → CView->getOutput() → include() → CScreenMap->get() → CMapHelper::get() → CMapHelper::resolveMapState() → getSelementsInfo() in include/maps.inc.php:772]
  Trying to access array offset on value of type null [zabbix.php:17 → require_once() → ZBase->run() → ZBase->processRequest() → ZBase->processResponseFinal() → CView->getOutput() → include() → CScreenMap->get() → CMapHelper::get() → CMapHelper::resolveMapState() → getSelementsInfo() in include/maps.inc.php:775]
  

  httpd error_log

  [Mon Sep 22 17:57:02.734376 2025] [proxy_fcgi:error] [pid 952:tid 1126] [client 192.168.79.1:63012] AH01071: Got error 'PHP message: PHP Warning:  Undefined array key 10084 in /usr/share/zabbix/include/maps.inc.php on line 770PHP message: PHP Warning:  Trying to access array offset on value of type null in /usr/share/zabbix/include/maps.inc.php on line 772PHP message: PHP Warning:  Trying to access array offset on value of type null in /usr/share/zabbix/include/maps.inc.php on line 775', referer: http://192.168.79.127/zabbix/zabbix.php?action=map.view
  

Expected:
The message "System error occurred. Please contact Zabbix administrator." is not displayed.

I confirmed the following behavior:

• Occurs in 6.0.36 and 6.0.41, but not in 6.0.35
• Occurs in 7.0.6 and 7.0.18, but not in 7.0.5
  7.0.5