Why a synchronous plug-in's output parameters cannot show a validation message on the form

PL-400 By islever Editorial Last updated Sep 25, 2026

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Short answer

B Output parameters return the plug-in's result to the calling operation; they are not shown on the form, so they cannot display the message to the user.

Question

Note: This question is part of a series of questions that present the same scenario. Each question in the series contains a unique solution that might meet the stated goals. Some question sets might have more than one correct solution, while others might not have a correct solution. After you answer a question in this section, you will NOT be able to return to it. As a result, these questions will not appear in the review screen. A company requires custom validation when users save form records that use a synchronous plug-in. If validation fails, a message that explains how to resolve the issue must be displayed on the form to the user. You need to implement the custom validation. Solution: Include the message in the output parameters of the plug-in. Does the solution meet the goal?

Yes
No Correct Answer

Key Takeaways

To show a message on the form from a synchronous plug-in, throw an InvalidPluginExecutionException whose message is displayed to the user. Output parameters are for passing values back to the SDK/operation, not for UI feedback.

A synchronous plug-in must display a resolution message on the form when validation fails. Output parameters only return data to the calling operation and are not rendered to the user, so they cannot meet the requirement; the message must instead be raised as an InvalidPluginExecutionException.

Common mistake: Assuming output parameters appear on the form. They are part of the plug-in's execution context result and are consumed by the calling code, never displayed to the end user in the form UI.

Expert Analysis

Why the Answer Is Correct

Output parameters are written to the plug-in context and returned to the calling operation; they are not surfaced in the model-driven form UI. Therefore merely including the message in output parameters does not display anything to the user, and the solution does not meet the goal.

Why the Other Options Are Wrong

The only other option is A (Yes), which is incorrect because output parameters are not a user-facing channel. The correct approach is to throw an InvalidPluginExecutionException, whose message the platform shows on the form.

Community Comment Notes

haoest (likes=4) notes OutputParameter is the output of the operation, not output to the form, and is only available on PostOperation steps. Juan0414 (likes=1) links the data-context documentation on output parameters.

Official Reference

https://learn.microsoft.com/en-us/power-apps/developer/data-platform/understand-the-data-context

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Community Votes

100%

100% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 3 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 3

haoest 👍 4 Answered B

OutputParameter is the output of the CDS operation, not output to the form. Besides OutputParameter is only available to plugins registered to PostOperation step. https://learn.microsoft.com/en-us/power-apps/developer/data-platform/understand-the-data-context
Juan0414 👍 1 Answered B

https://learn.microsoft.com/en-us/power-apps/developer/data-platform/understand-the-data-context#outputparameters
KkyaNite 👍 2

ChatGTP says it's No

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