Power Platform Community Forum Thread Details

Hello, I have added a subgrid (milestones) on my parent form(charter) . However, the +Add New Key Milestones button on the subgrid does not work pop open my related table (milestones) or the quick create form that is on the milestones table. I have enabled quick create forms on both tables and related the Milestones to have a many to one relationship with the charter table as there should be many milestones for one charter.

Categories:

Building Power Apps

Hi @VC-27022006-0,

Why the “Add New” button does nothing
In model-driven apps, a subgrid cannot create a related record unless:

The parent record is already saved (has a real GUID).
The subgrid is configured using the correct relationship (N:1 lookup).
The quick create form for the child table (Milestones) is enabled and published.
The user has create permissions on the child table.

If any one of the above is missing, the button silently does nothing.

Step-by-step fixes
Save the Charter record first (most common fix)
Ensure the subgrid is using the correct relationship
Verify that Quick Create is enabled for Milestones
Ensure the Milestone lookup back to Charter is on the Quick Create form
Check Security Roles (for permission)
Try switching to the old (classic) related records dialog (Rare cases in 2025/2026 UI updates cause issues.)

Your screenshot shows, The Charter form is New (unsaved), this strongly suggests the record is not saved yet, which blocks the subgrid from opening the Milestones form.

Try this sequence:

Fill required Charter fields
Click Save
Go to the Key Milestones tab
Click + New Key Milestones

Let us know if it helps!

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