SMIME Extension Error in EDGE

1. Certificate Configuration Repair
Clearing cached certificates
powershell
certmgr.msc → Remove all expired certificates from ‘Personal’ and ‘Trusted Publishers’.
2. Re-register extensions
powershell
reg add ‘HKLM\Software\Policies\Microsoft\Edge\Extensions\ghbmnnjooekpmoecnnnilnnbdlolhkhi’ /v installation_mode /t REG_SZ /d force_ installed /f installed /f
3. Group Policy Configuration
Force enable S/MIME
xml
<Policy>
  <ExtensionInstallForcelist>
    <Item>
      <Id>ghbmnnjooekpmoecnnnnilnnbdlolhkhi</Id>
   <UpdateUrl>https://edge.microsoft.com/extensionwebstorebase/v1/crx</UpdateUrl>
    </Item
  </ExtensionInstallForcelist
</Policy>
Run the HTML
4. Certificate auto-selection rules
powershellSet-SmimeConfig -OWACertificateIssuingCA ‘CN=YourCA, DC=domain, DC=com’