

Input & Visibility
The menu does not appear when I press the input key.
Check the following:- If you have deactivated the “Use System Defined Main Widget” option, you must implement the
BPI_FDM_ComponentOwnerinterface and theGet FDM Widgetfunction in the actor where you add the Component. - Ensure
AC_FDM_Componentis added to the correct actor (usually the Player Character or Controller) and Input Action Events bound correctly. - Verify that
InitializeFDMComponentis called during BeginPlay or initialization. - If you disabled
Auto Bind Navigation Mapping Contextin your config, you must callBind Navigation Mapping Contextmanually after you called the initialization function. - Make sure
Navigation Input Mapping Contextin the Config file is valid. - If
Widget Should Be Hidden by Defaultis enabled, ensureRequestShowMenuis being called. - Increasing
Navigation Mapping Context Prioritymight solve this problem.
The menu appears but does not respond to input.
In addition to methods that could solve the previous problem check the following:- Check that no other system is currently consuming input (e.g., modal widgets, pause menu).
- Confirm
Should Process FDM Inputfunction inAC_FDM_Componentreturns true.
The Menu appears twice
This usually means:Use System Defined Main Widgetis still enabled, and- You also manually added
WBP_FDM_Widgetto your own HUD.
Which actor should implement BPI_FDM_ComponentOwner?
Typically the Player Character or Player Controller — whichever owns the AC_FDM_Component.
Slot Switch Menu does not open
- Check that the container has more than one slot.
- Verify the
Change Slot Mapping Contextis active. - Ensure that the input is not being consumed by another system. Increasing
Change Slot Mapping Context Prioritymight solve this problem.
My entries are not being added to the menu.
- Make sure the source object implements
BPI_FDM_EntrySourceObject. - Verify that
GetEntryMetadatareturns a valid metadata struct. - Check that the Layout Tag in metadata exists in
Layout Datain the config.
Layout & Placement
My entry appears in the wrong container or direction
- Check the Gameplay Tag in the entry metadata.
- Verify that the tag maps to the intended container location in
Layout Data. - Remember: Layout initialization order determines proximity to the center.
Entries overlap or spacing looks wrong
- Verify
Padding Between SlotsandPadding Between Containers. - Check that all Slot Widgets use consistent size or scaling rules.
- Ensure no external layout panels override widget size.
The slot animation looks jittery or overshoots
- Reduce
Slot Interp SpeedorAccordion Animation Interp Speed. - Make sure animation logic is not running in Event Tick unnecessarily.
- Avoid simultaneously driving position from animation and manual interpolation.
Selection
Selection feels too fast / too sensitive or Selection triggers while navigating quickly between containers
- Enable
Use Debounced Selection. - Increase
Debounce Duration in Seconds.
Performance
Is this system expensive?
No — the menu only updates when:- Entries change,
- Selection changes,
- The menu is visible.
Networking
Is it safe to use in multiplayer?
This system is UI-side and non-replicated by default. It is safe for multiplayer, but entry and selection replication must be handled by the game.Integration
Can I use this with my own inventory system?
Yes. Any object can be an entry as long as it implementsBPI_FDM_EntrySourceObject and provides valid metadata.