diff --git a/app/react/components/ui.jsx b/app/react/components/ui.jsx
index 82b277d..aaac9f0 100644
--- a/app/react/components/ui.jsx
+++ b/app/react/components/ui.jsx
@@ -232,12 +232,18 @@ function Ui({disconnected}) {
   ]);
   usePacket('EcsChange', onEcsChangePacket);
   const onTickPacket = useCallback(async (payload, client) => {
-    if (0 === Object.keys(payload.ecs).length) {
+    if (!ecsRef.current || 0 === Object.keys(payload.ecs).length) {
       return;
     }
     latestTick.current = Promise.resolve(latestTick.current).then(async () => {
-      await ecsRef.current.apply(payload.ecs);
-      client.emitter.invoke(':Ecs', payload.ecs);
+      try {
+        await ecsRef.current.apply(payload.ecs);
+        client.emitter.invoke(':Ecs', payload.ecs);
+      }
+      catch (error) {
+        ecsRef.current = undefined;
+        console.error('tick crash', error);
+      }
     });
   }, [ecsRef]);
   usePacket('Tick', onTickPacket);
@@ -361,7 +367,7 @@ function Ui({disconnected}) {
     };
   }, []);
   const computePosition = useCallback(({clientX, clientY}) => {
-    if (!gameRef.current || !mainEntityRef.current) {
+    if (!gameRef.current || !mainEntityRef.current || !ecsRef.current) {
       return;
     }
     const {top, left, width} = gameRef.current.getBoundingClientRect();