The step that the server administrator should perform before resolving the issue is to determine the probable causes. This step is part of the troubleshooting process that follows a logical and systematic approach to identify and solve problems with servers and applications. The troubleshooting process consists of several steps, such as:
Identify the problem: Gather information from various sources, such as users, logs, or alerts, to understand the symptoms and scope of the problem.
Establish a theory of probable cause: Analyze the information and formulate one or more possible causes of the problem based on evidence or experience.
Test the theory to determine cause: Perform tests or experiments to verify or eliminate each possible cause until the root cause is found.
Establish a plan of action to resolve the problem and implement the solution: Design and execute a plan to fix the problem using appropriate tools and techniques.
Verify full system functionality and implement preventive measures: Confirm that the problem is resolved and that no other issues arise as a result of the solution. Implement preventive measures to avoid recurrence of the problem or improve performance.
Document findings, actions, and outcomes: Record the details of the problem, its cause, its solution, and its outcome for future reference or knowledge sharing. References: [CompTIA Server+ Certification Exam Objectives], Domain 6.0: Troubleshooting, Objective 6.1: Given a scenario involving server hardware issues (e.g., power supply failure), troubleshoot using appropriate tools.

Application consistent backup is a method of backing up data that ensures the integrity and consistency of the application state. It involves notifying the application to flush its data from memory to disk and quiescing any write operations before taking a snapshot of the data. If the databases were not backed up to be application consistent, they might contain incomplete or corrupted data that cannot be restored properly.
References:
CompTIA Server+ Certification Exam Objectives1, page 12
What is Application Consistent Backup and How to Achieve It2
Application-Consistent Backups3

The best way to protect an organization against social engineering is to provide recurring training and support.
Social engineering is a type of attack that exploits human psychology and behavior to manipulate people into divulging confidential information or performing malicious actions. Social engineering can take various forms, such as phishing emails, phone calls, impersonation, baiting, or quid pro quo. The best defense against social engineering is to educate and empower the employees to recognize and avoid common social engineering techniques and report any suspicious activities or incidents. Recurring training and support can help raise awareness and reinforce best practices among the employees.

The server is not joined to the domain is causing the issue. A domain is a logical grouping of computers that share a common directory database and security policy on a network. Active Directory is a Microsoft technology that provides domain services for Windows-based computers. To use Active Directory credentials to log on to a server, the server must be joined to the domain that hosts Active Directory. If the server is not joined to the domain, it will not be able to authenticate with Active Directory and will only accept local accounts for logon. To join a server to a domain, the administrator must have a valid domain account with sufficient privileges and must know the name of the domain controller that hosts Active Directory.