Symptoms
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Updating Plesk Obsidian for Windows fails:
Error: The installation of the package 'modsecurity' failed with code 1603. (upgrade: Upgrading ModSecurity IIS Module...)
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Creating new domains or subdomains in Plesk fails:
Domain example.com creation failed
String must not be empty
.....
Cause
ModSecurity modules were manually removed from IIS - they are missing in Internet Information Services (IIS) Manager > server_name > Modules.
Resolution
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Connect to the server using RDP.
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Go to Start > Server Manager > Tools > Internet Information Services (IIS) Manager.
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Register ModSecurity modules:
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Go to server_name > Modules:
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Click Configure Native Modules > Register:
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Register modules:
name: ModSecurity IIS (32bits)
path:C:WindowsSystem32inetsrvModSecurityIIS.dllname: ModSecurity IIS (64bits)
path:C:WindowsSysWOW64inetsrvModSecurityIIS.dll
-
-
Restart IIS by opening CMD as Administrator and executing the command:
iisreset /restart
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Complete the update or create a domain/subdomain anew.
Additional information
Instead of removing ModSecurity modules directly from IIS, ModSecurity can be disabled via Plesk: How to disable ModSecurity in Plesk?