diff --git a/plugs/core/debug.ts b/plugs/core/debug.ts
index ccfa62c..0587793 100644
--- a/plugs/core/debug.ts
+++ b/plugs/core/debug.ts
@@ -60,7 +60,7 @@ export async function showLogsCommand() {
       serverDiv.scrollTop = serverDiv.scrollHeight;
 
       self.close = () => {
-        sendEvent("log:hide");
+        syscall("event.dispatch", "log:hide");
       };
 
       syscall("system.getEnv").then((env) => {
diff --git a/plugs/markdown/assets/handler.js b/plugs/markdown/assets/handler.js
index 3114713..d685791 100644
--- a/plugs/markdown/assets/handler.js
+++ b/plugs/markdown/assets/handler.js
@@ -1,9 +1,15 @@
 document.getElementById("root").addEventListener("click", (e) => {
   // console.log("Got click", e.target)
   const dataSet = e.target.dataset;
-  if(dataSet["onclick"]) {
-    sendEvent("preview:click", dataSet["onclick"]);
-  } else if(dataSet["pos"]) {
-    sendEvent("preview:click", JSON.stringify(["pos", dataSet["pos"]]));
+  if (dataSet["onclick"]) {
+    syscall("event.dispatch", "preview:click", dataSet["onclick"]).catch((e) =>
+      console.log("Error", e)
+    );
+  } else if (dataSet["pos"]) {
+    syscall(
+      "event.dispatch",
+      "preview:click",
+      JSON.stringify(["pos", dataSet["pos"]])
+    ).catch((e) => console.log("Error", e));
   }
-})
\ No newline at end of file
+});
diff --git a/web/components/panel.tsx b/web/components/panel.tsx
index d494e05..1193256 100644
--- a/web/components/panel.tsx
+++ b/web/components/panel.tsx
@@ -62,6 +62,7 @@ window.addEventListener("message", (message) => {
   }
 });
 
+// DEPRECATED: Use syscall("event.dispatch", ...) instead
 function sendEvent(name, ...args) {
   window.parent.postMessage({ type: "event", name, args, }, "*");
 }
@@ -137,12 +138,20 @@ export function Panel({
         case "syscall": {
           const { id, name, args } = data;
           editor.system.localSyscall("core", name, args).then((result) => {
+            if (!iFrameRef.current?.contentWindow) {
+              // iFrame already went away
+              return;
+            }
             iFrameRef.current!.contentWindow!.postMessage({
               type: "syscall-response",
               id,
               result,
             });
           }).catch((e: any) => {
+            if (!iFrameRef.current?.contentWindow) {
+              // iFrame already went away
+              return;
+            }
             iFrameRef.current!.contentWindow!.postMessage({
               type: "syscall-response",
               id,