undefined cannot be transmitted via json, so we use null to reset the movement history instead

CHANGELOG.md

@@ -1,3 +1,8 @@
+## In development
+### Bugfixes
+- The reset movement history button now resets the movement history for all players, not just for the GM
+
+
 ## 1.6.1
 ### API
 - Added `onMovementHistoryUpdate` callback to Speed Providers, that allows them to perform game systems specific improvements to the movement history

src/movement_tracking.js

@@ -86,8 +86,8 @@ export async function resetMovementHistory(combat, combatantId) {
 	const dragRulerFlags = combatant.flags.dragRuler;
 	if (!dragRulerFlags)
 		return;
-	dragRulerFlags.passedWaypoints = undefined;
-	dragRulerFlags.trackedRound = undefined;
-	dragRulerFlags.rulerState = undefined;
+	dragRulerFlags.passedWaypoints = null;
+	dragRulerFlags.trackedRound = null;
+	dragRulerFlags.rulerState = null;
 	await updateCombatantDragRulerFlags(combat, [{_id: combatantId, dragRulerFlags}]);
 }