The write-back table/view always need to have a column for transaction stamp of the current user and a column for a datetime transaction timestamp.

NB! The two stamp columns need to the last two columns in the table/view.

For allowing a current user stamp with write-backs, a calculated measure needs to be made using the following DAX:

User = USERPRINCIPALNAME()

For Performance optimization with large dimensions:

User = IF([VALUE], USERPRINCIPALNAME())

The calculated measure needs to be added in the field “User” for the visual as illustrated below:

If the calculated measure for user is not made a current user stamp will not be added on write-backs.

NB! Columns for current user and timestamp both need to be present in the table/view, regardless of whether the current user stamp is being utilized.

Key this in mind:

You can only type data if it is on the lowest level (leaf level). Thus not on “All” level
Last two columns are need for the transactions stamp (username and datetime)
Switch between the native Power BI Matrix and accoPLANNING to verify issues in the data configurations. They should show the same.
Test your database connection in management studio or excel if you have issues with the settings in the connection to the writeback table.

Add and configure the visual