The answer is that the stack creation timed out or was manually cancelled. This is because the "Resource creation cancelled" error in CloudFormation specifically indicates that the overall stack operation was halted—either by reaching the specified timeout limit or by a user-initiated cancellation—before the EC2 instance resource could finish provisioning. Crucially, a UserData script failure does not cause this error; CloudFormation only tracks the resource's launch state, not the success of scripts inside it, unless you have explicitly attached a CreationPolicy or WaitCondition. On the AWS Certified DevOps Engineer Professional DOP-C02 exam, this question tests your ability to distinguish between CloudFormation lifecycle errors and application-level failures, a common trap where engineers mistakenly blame UserData. Remember the key distinction: CloudFormation manages infrastructure creation, not software configuration. Memory tip: "Cancelled means the clock ran out or you hit stop—UserData is just a passenger, not the driver."
DOP-C02 Configuration Management and IaC Practice Question
This DOP-C02 practice question tests your understanding of configuration management and iac. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A DevOps engineer is troubleshooting a CloudFormation stack creation failure. The stack includes an EC2 instance with a UserData script that installs software. The stack creation fails with the error: 'The following resource(s) failed: EC2Instance (AWS::EC2::Instance) – Resource creation cancelled'. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The stack creation timed out or was manually cancelled
Option D is correct because Resource creation cancelled indicates the stack creation timed out or was manually cancelled. UserData scripts do not affect CloudFormation resource status unless the instance is created with a CreationPolicy or WaitCondition. Option A is incorrect because UserData failure does not cause a CloudFormation error. Option B is incorrect because Resource creation cancelled is not due to API rate limiting. Option C is incorrect because missing IAM role would cause an 'AccessDenied' error, not cancellation.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The EC2 instance type is not supported in the region
Why it's wrong here
Unsupported instance type would cause a different error.
✗
The IAM role attached to the instance lacks permissions
Why it's wrong here
Permission issues would cause an AccessDenied error.
✓
The stack creation timed out or was manually cancelled
Why this is correct
Resource creation cancelled typically indicates a timeout or manual cancellation.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The UserData script failed due to a syntax error
Why it's wrong here
UserData failure does not cause CloudFormation to cancel the resource creation; it only logs errors.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Got this wrong? Here's your next step.
Identify which DOP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Configuration Management and IaC — This question tests Configuration Management and IaC — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The stack creation timed out or was manually cancelled — Option D is correct because Resource creation cancelled indicates the stack creation timed out or was manually cancelled. UserData scripts do not affect CloudFormation resource status unless the instance is created with a CreationPolicy or WaitCondition. Option A is incorrect because UserData failure does not cause a CloudFormation error. Option B is incorrect because Resource creation cancelled is not due to API rate limiting. Option C is incorrect because missing IAM role would cause an 'AccessDenied' error, not cancellation.
What should I do if I get this DOP-C02 question wrong?
Identify which DOP-C02 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This DOP-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DOP-C02 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.