Thank you for your question and reaching out. I can understand you are having issues related to for CA web enrollment.
- Please DCOM permissions
Open an MMC console and add the Component Services snap-in. Open -> Component Services and DCOM Config. Then find the CertSRV Request. Check the Properties, Security and Access Permissions. There are separate permissions for Local and Remote access.
- Log onto the CA, check whether Remote Procedure Call services (including RPC and RPCLocator services) are running, if not, start them manually.
- Disable any Antivirus program or Windows firewall you may have for temporary purpose.
- Ensure ports TCP 135 and randomly allocated high TCP ports are not blocked, or you may temporarily disable firewall on the CA to test.
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