How can I troubleshoot a 'cannot be parsed did not connect' error related to a MongoDB URI?

Start by carefully reviewing the connection string for any typos or missing elements. Use a URI validator (online tools are available) to check its syntax. Ensure the username and password (if used) are correctly encoded, especially if they contain special characters. Verify the hostname and port are reachable from your application server. Finally, check your MongoDB server's firewall settings to ensure connections are allowed.