Quick Answer
The answer is that the data source credentials were not configured in the on-premises data gateway. This error occurs because Power BI scheduled refresh for a SQL Server database requires a gateway to bridge the cloud service with your on-premises network, and the gateway itself must have valid, stored credentials for that specific data source. Even if the scheduled refresh is correctly set to 6:00 AM, the refresh will fail with a "credentials invalid" error if the gateway’s data source settings are missing or incorrect. On the PL-300 exam, this scenario tests your understanding of gateway configuration versus schedule setup—a common trap is assuming the refresh schedule alone is sufficient. Remember the memory tip: "Gateway first, schedule second" to avoid confusing connectivity setup with timing.
This PL-300 practice question tests your understanding of prepare the data. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
You are preparing a Power BI dataset that uses a SQL Server database as the source. Your manager asks you to ensure that the dataset refreshes automatically every morning at 6:00 AM. You have configured a scheduled refresh in the Power BI service. However, after the first scheduled refresh, you notice that it failed with an error: 'The data source credentials are invalid.' What is the most likely cause and solution?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "first"
Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
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.
The scheduled refresh time is not set correctly.
Why wrong: The refresh did trigger, so time is set.
The data source credentials are not configured in the gateway.
Credentials must be set for the gateway to connect.
An on-premises data gateway is not installed.
Why wrong: If no gateway, error would be different.
The dataset is too large for scheduled refresh.
Why wrong: Size would cause timeout, not credential error.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
The data source credentials are not configured in the gateway.
The error 'The data source credentials are invalid' indicates that the credentials stored in the Power BI service for the data source are incorrect or missing. Since the dataset uses a SQL Server database, which is an on-premises data source, the credentials must be configured within the on-premises data gateway settings in the Power BI service. Option B correctly identifies that the gateway credentials were not set up, causing the refresh to fail despite the scheduled refresh being configured.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
The scheduled refresh time is not set correctly.
Why it's wrong here
The refresh did trigger, so time is set.
The data source credentials are not configured in the gateway.
Why this is correct
Credentials must be set for the gateway to connect.
Clue confirmation
The clue words "first", "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
An on-premises data gateway is not installed.
Why it's wrong here
If no gateway, error would be different.
The dataset is too large for scheduled refresh.
Why it's wrong here
Size would cause timeout, not credential error.
Common exam traps
The trap here is that candidates often confuse the scheduled refresh configuration with the data source credentials, assuming that setting the refresh time is sufficient, or they mistakenly think the error relates to the user's Power BI login rather than the gateway's stored credentials for the SQL Server database.
Detailed technical explanation
When using an on-premises data gateway, the Power BI service stores encrypted credentials for the data source within the gateway's configuration. The gateway uses these credentials to connect to the SQL Server database during refresh. If the credentials are not provided or are incorrect in the gateway's data source settings, the gateway cannot authenticate, leading to the 'credentials invalid' error. This is distinct from the credentials used to sign in to the Power BI service itself.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Prepare the data — study guide chapter
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FAQ
Prepare the data — This question tests Prepare the data — Read the scenario before looking for a memorised answer..
The correct answer is: The data source credentials are not configured in the gateway. — The error 'The data source credentials are invalid' indicates that the credentials stored in the Power BI service for the data source are incorrect or missing. Since the dataset uses a SQL Server database, which is an on-premises data source, the credentials must be configured within the on-premises data gateway settings in the Power BI service. Option B correctly identifies that the gateway credentials were not set up, causing the refresh to fail despite the scheduled refresh being configured.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "first", "most likely". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 24, 2026
This PL-300 practice question is part of Courseiva's free Microsoft 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 PL-300 exam.
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