HTTP 500 Error After Production Cutover Due to MongoDB Configuration and Apache Access Restrictions

Original Question or Issue:

After cutting over FileCloud production to new hosts, users were unable to access the FileCloud web interface and received an HTTP 500 error.

Environment:

Steps to Reproduce:

Error or Log Message:

HTTP 500 Internal Server Error

Apache Error Log:
AH01797: client denied by server configuration: /var/www/html/ui

Defect or Enhancement Number:

Cause:

Two separate issues were identified:

The MongoDB connection string in cloudconfig.php contained an incorrect password, causing FileCloud to fail connecting to the database and resulting in an HTTP 500 error.
Apache was blocking requests from the F5 load balancer IP addresses. The Apache logs repeatedly showed:
AH01797: client denied by server configuration: /var/www/html/ui

The denied requests originated from the F5 load balancer subnet ranges.

Resolution or Workaround:

Verify FileCloud connectivity using curl against the application URL.
Review the MongoDB connection string in cloudconfig.php and ensure the correct database credentials are configured.
If OpenSSL-related warnings are observed, verify the server OpenSSL version and confirm the following MongoDB URI option is configured if required:
"tlsDisableOCSPEndpointCheck" => true
Review Apache error logs for access restriction messages.
Update the Apache configuration to allow traffic from the load balancer subnets.

Notes:

If the environment is behind an F5 or other load balancer, review Apache access control settings and ensure the load balancer IP ranges are explicitly permitted.
After applying the configuration changes, FileCloud became accessible and functioned normally.