Can't disable Exchange protection Management.

Hi @Андрей Михалевский,

Welcome to the Microsoft Q&A platform!

Based on your description, you are experiencing a common problem with the Exchange Management Shell (EMS) when trying to disable Extended Protection. Here are some steps to help you troubleshoot and resolve this issue:

1. Make sure you are running the Exchange Management Shell as an administrator. Right-click the EMS shortcut and select "Run as Administrator".
2. Make sure you have the latest version of the ExchangeExtendedProtectionManagement.ps1 script. Microsoft frequently updates these scripts to fix bugs and improve functionality.
3. Run the script with the -PrerequisitesCheckOnly parameter to ensure that all prerequisites are met:

.\ExchangeExtendedProtectionManagement.ps1 -PrerequisitesCheckOnly 

1. The error message "Length cannot be less than zero. Parameter name: Length" indicates that there may be a problem with the script or environment. Check the detailed error log for more information.
2. Sometimes, reinstalling the latest cumulative update (CU) or security update can resolve EMS issues. Make sure your server is fully updated.
3. If the script has partially applied changes, you may need to roll back the configuration. Restore the IIS application configuration using the following command:

.\ExchangeExtendedProtectionManagement.ps1 -RollbackType "RestoreIISAppConfig" 

1. Ensure that the TLS settings on the Exchange server are consistent and meet the requirements for Extended Protection.

If these steps do not resolve the issue, please share any specific error messages or logs you see and I can help further!

Please feel free to contact me for any updates. And if this helps, don't forget to mark it as an answer.

Best,

Jake Zhang