Power Platform Community Forum Thread Details

This is what my research has led me to using web search and GenAI . Let me know if this helps.

I am quoting all the sources so that you may benefit more by referring to original sources.

The error "We’re sorry. You cannot directly do 'Create' operation to 'msdyn_projecttask'. Try editing it through the Resource editing UI via Project." is a known limitation in Project for the Web and Dynamics 365 Project Operations: you cannot create or update msdyn_projecttask directly via standard Dataverse or Power Automate actions. This is by design to maintain data integrity of scheduling entities.powerplatform+2

Why This Happens

The Project and Task tables in Dataverse are managed via the Project scheduling engine, not by direct Dataverse CRUD operations.techcommunity.microsoft+2

Direct creation or update of tasks bypasses essential scheduling logic, hence the restriction.

Workarounds and Best Approach

Use Project Schedule APIs:

To programmatically add tasks, you must leverage the official Project Schedule APIs (sometimes called "Scheduling entities API").

The key endpoint is msdyn_PSSCreateV1 for creating tasks, and you must first start an Operation Set using msdyn_CreateOperationSetV1.anttipajunen+2

You can orchestrate this in Power Automate with a custom connector or via HTTP calls.

Steps Overview:

Start an operation set (msdyn_CreateOperationSetV1).

Use the operation set ID to add your new task (msdyn_PSSCreateV1).

Execute the operation set (msdyn_ExecuteOperationSetV1) to commit changes.dynamics+2

Confirm the created task appears in Project for the Web UI.

Microsoft’s documentation provides samples and schemas for these APIs.learn.microsoft+2

Sample Reference

Method	Supported?	Notes
Direct Dataverse Create/Update	No	Throws the error you receivedpowerplatform+2
Project Schedule APIs	Yes	Requires custom connector or HTTP requests from Power Automateanttipajunen+2
Manual Project UI Edit	Yes	Always supported