We are not able to view and assist with moderation issues on your Realm directly. However, we do have a guide to help you with some of the Realm moderation options built in. You can access these by clicking the Edit Realm Icon next to your Realm in the server list. 
 
1. Close the Realm - This prevents anyone from joining your Realm until you open it again. 
2. Set "Guest" permissions by default - Invitees that join your Realm will be unable to make any changes to the world, such as breaking blocks, griefing, or making other undesirable changes. 
3. Restore from a previous backup - You may be able to roll back to a previous backup before any undesired changes were made. 
 
Realms also uses an invitation-only system that helps prevent unauthorized access. Access and per-player permissions can be managed through your Realms admin settings. 
 
For more information, you can visit our Realms FAQ as well as our Realms Admin Options articles.  

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