Quick answer: Unreal Blueprint actor's Event Tick running before its async-loaded class fully spawned? Tick fires before BeginPlay completes - guard tick with a 'ready' flag.
Newly spawned actor's tick references components that haven't constructed; crash.
Guard tick with ready flag
if (!bReady) return;Set bReady in BeginPlay; tick skips until then.
Or disable tick until ready
SetActorTickEnabled(false) at construction; enable in BeginPlay. Cleaner.
Audit tick prerequisites
Each tick's reads. If any is BeginPlay-initialized, guard or disable.
“Tick lifecycle overlaps construction. The overlap is the bug surface.”
If your actor's Tick assumes BeginPlay ran, the guard pattern is non-optional. Document.