The Assistant Manager controls how painting, layer addition, and applying filters has an effect on layers in your document. The Manager lets you choose whether or not to be alerted of layer operations as they occur.
Alert messages inform you that Affinity Photo has performed an action that you need to be aware of. This is as a result of the last operation you performed. Assistant Manager can decide the default type of action to take. While in Photo Persona, several types of operation can lead to different actions.
Painting with no layer selected: Creates a new pixel layer for your brush strokes using 'Add new pixel layer and paint' if there is no pixel or vector layer selected; 'Take no action' means that no pixel painting is allowed.
Erasing from vector layers: Erases on a created layer mask applied to your vector layer, immediately rasterize the vector layer and erase directly on it, or take no action.
Other brushes on vector layers: For retouching pixel brushes (e.g., Burn Brush Tool, Smudge Brush Tool, etc.), any applied brush stroke rasterizes the vector layer by default. You can change this behavior by selecting 'Take no action' which doesn't convert the layer or apply the stroke.
Brush tool sharing: Choose whether a selected brush is shared between tools of a similar nature (e.g. Dodge, Burn and Sponge Brush Tools), shared across all tools, or each tool's brush is set independently.
Applying filters to vector layers: For effect and retouch filters from the Filters menu, applying a filter to a vector layer rasterizes it by default. You can change this behavior by selecting 'Take no action' which doesn't convert the layer or apply the filter.
Adding adjustment layer to selection: If you've created a selection, any adjustment applied to the selection is added as a new adjustment layer above the currently selected layer or made a child adjustment layer of the selected layer instead. With no layer selected, a new adjustment layer is added to the top of the layer stack in both instances.
Adding mask layer to selection: Analogous to 'Adding adjustment layer to selection' above, but for mask layers.
Adding filter layer to selection: Analogous to 'Adding adjustment layer to selection' above, but for filter layers.
To change Assistant Manager settings:
From the View menu, click Assistant Manager.
Select options from the relevant option's pop-up menu.
To switch off alerts or the Assistant Manager completely:
From the View menu, click Assistant Manager.
Uncheck Alert when assistant takes an action or Enable assistant, respectively.