IsValid node not working

ShaytanJr · June 19, 2025, 7:02pm

In 1/10 ViewPort Simulations, I get an Infinite Loop error in this custom event that destroys overlapping rooms when I build the level. Even after executing the IsValid node, I keep getting these two errors from the blueprint:

Blueprint Runtime Error: "Attempted to access BP_Room_C_158 via property K2Node_CustomEvent_LastSpawnRoom, but BP_Room_C_158 is not valid (pending kill or garbage)". Node:  Branch Graph:  ForEachLoop Function:  Execute Ubergraph BP Procedural Dungeon Generator Blueprint:  BP_ProceduralDungeonGenerator

Blueprint Runtime Error: "Accessed None". Node:  Branch Graph:  ForEachLoop Function:  Execute Ubergraph BP Procedural Dungeon Generator Blueprint:  BP_ProceduralDungeonGenerator

This is the only ForEachLoop that has access to the variable LastSpawnRoom:

For some reason, the ForEachLoop keeps accessing the same actor I just destroyed, even though the previous event should have spawned a new actor and set it as the Last Spawn Room.

The game uses random seeds, and only some seeds show this problem.

PREDALIEN · June 19, 2025, 7:45pm

Try saving the array (Children pin) to a variable and then connecting it to the loop node.

Rev0verDrive · June 19, 2025, 8:42pm

is valid (still exists somewhere) → Is pending Kill (in garbage, but not flushed yet)

ShaytanJr · June 19, 2025, 8:46pm

This got rid of the two invalid actor errors for the LastSpawnRoom variable. Could you explain why this error happens or why this solution works? I want to prevent this kind of error if possible.

Edit: The AccessedNone error is now appearing for a different variable:

I think this is where the new error is happening:

Rev0verDrive · June 19, 2025, 8:59pm

This is because each time the Loop fires for a new index its “Getting” a fresh copy from the Get Children Components node.

Validate Chosen Exit. It’s currently empty/null, thus the error. Go back to the code that sets it. Issue is there.