The correctness of the LDAP server address and port number configured in Tableau Server A common and primary aspect to check when troubleshooting LDAP integration issues is the correctness of the LDAP server address and port number in the Tableau Server configuration. Incorrect server address or port configuration can lead to failed connections and authentication problems, making it a critical first step in the troubleshooting process. Option A is incorrect be-cause while network speed and latency are important, they are not usually the first aspect to be checked in LDAP integration issues. Option B is incorrect as software version compatibility, although important, is usually validated during the initial setup and is less likely to be the cause of sudden integration issues. Option D is incorrect because firewall settings on client machines are not typically related to LDAP authentication issues on the server side.