diff --git a/macrovision.html b/macrovision.html
index 8778ccea..9f7402f8 100644
--- a/macrovision.html
+++ b/macrovision.html
@@ -39,7 +39,16 @@
 <body class="toggle-bottom-name toggle-top-name">
   <script type="text/javascript">
     window.onerror = function(msg, url, line, col, error) {
-      alert("An error occured. If you're on a computer, hit F12 to open the developer tools, click the Console tab, and send the red text to chemicalcrux. If you're on mobile, screenshot this instead:\n\n" + msg + "\n" + url + "\n" + "line: " + line + "\n" + "col: " + col + "\nerror: " + error);
+      if (firsterror) {
+        firsterror = false;
+        alert("An error occured. If you're on a computer, hit F12 to open the developer tools, click the Console tab, and send the red text to chemicalcrux. If you're on mobile, screenshot this instead:\n\n" + msg + "\n" + url + "\n" + "line: " + line + "\n" + "col: " + col + "\nerror: " + error);
+      }
+    }
+    window.onunhandledrejection = function(e) {
+      if (firsterror) {
+        firsterror = false;
+        alert("An error occured. If you're on a computer, hit F12 to open the developer tools, click the Console tab, and send the red text to chemicalcrux. If you're on mobile, screenshot this instead:\n\n" + e.reason);
+      }
     }
   </script>
   <input hidden id="file-upload-picker" type='file' multiple>
diff --git a/macrovision.js b/macrovision.js
index d60cd12c..e28e6abf 100644
--- a/macrovision.js
+++ b/macrovision.js
@@ -5,6 +5,8 @@ let prevSelectedEntity = null;
 
 let entityIndex = 0;
 
+let firsterror = true;
+
 let clicked = null;
 let movingInBounds = false;
 let dragging = false;
@@ -3179,7 +3181,6 @@ document.addEventListener("DOMContentLoaded", () => {
 
     document.querySelector("#copy-screenshot").addEventListener("click", e => {
         copyScreenshot();
-        toast("Copied to clipboard!");
     });
 
     document.querySelector("#save-screenshot").addEventListener("click", e => {
@@ -5095,7 +5096,11 @@ function copyScreenshot() {
             new ClipboardItem({
                 "image/png": blob
             })
-        ]);
+        ]).then(e => 
+            toast("Copied to clipboard!"))
+            .catch(e => {
+            toast("Couldn't write to the clipboard. Make sure the screenshot completes before switching tabs.")
+        })
     });   
     drawScales(false);
 }
