diff --git a/package-lock.json b/package-lock.json
index de70d98..8f9e5ee 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10592,9 +10592,9 @@
       }
     },
     "svelte": {
-      "version": "3.42.3",
-      "resolved": "https://registry.npmjs.org/svelte/-/svelte-3.42.3.tgz",
-      "integrity": "sha512-pbdtdNZEx2GBqSM6XEgPoHbwtvWBwFLt/1bRmzsyXZO+i424wFnPe7O5B3GOJDPFSxPRztumAW3mL5LPzecWUg=="
+      "version": "3.42.4",
+      "resolved": "https://registry.npmjs.org/svelte/-/svelte-3.42.4.tgz",
+      "integrity": "sha512-DqC0AmDdBrrbIA+Kzl3yhBb6qCn4vZOAfxye2pTnIpinLegyagC5sLI8Pe9GPlXu9VpHBXIwpDDedpMfu++epA=="
     },
     "svelte-dev-helper": {
       "version": "1.1.9",
diff --git a/package.json b/package.json
index 3ce04cc..07ca9ed 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,7 @@
     "scratch-svg-renderer": "git://github.com/TurboWarp/scratch-svg-renderer.git#develop",
     "scratch-vm": "git://github.com/TurboWarp/scratch-vm.git#develop",
     "sha.js": "^2.4.11",
-    "svelte": "^3.42.3"
+    "svelte": "^3.42.4"
   },
   "devDependencies": {
     "@babel/core": "^7.15.0",
diff --git a/src/p4/SelectProject.svelte b/src/p4/SelectProject.svelte
index 22d2123..9379a7f 100644
--- a/src/p4/SelectProject.svelte
+++ b/src/p4/SelectProject.svelte
@@ -134,9 +134,12 @@
     e.target.select();
   };
   const handleDrop = ({detail: dataTransfer}) => {
-    $type = 'file';
-    files = dataTransfer.files;
-    fileInputElement.files = files;
+    const name = dataTransfer.files[0].name;
+    if (name.endsWith('.sb') || name.endsWith('.sb2') || name.endsWith('.sb3')) {
+      $type = 'file';
+      files = dataTransfer.files;
+      fileInputElement.files = files;
+    }
   };
 </script>
 
diff --git a/src/packager/download-project.js b/src/packager/download-project.js
index da873a8..0495e97 100644
--- a/src/packager/download-project.js
+++ b/src/packager/download-project.js
@@ -12,6 +12,16 @@ const identifyProjectType = (projectData) => {
   return null;
 };
 
+const isScratch1Project = (uint8array) => {
+  const MAGIC = 'ScratchV';
+  for (let i = 0; i < MAGIC.length; i++) {
+    if (uint8array[i] !== MAGIC.charCodeAt(i)) {
+      return false;
+    }
+  }
+  return true;
+};
+
 const unknownAnalysis = () => ({
   stageVariables: {},
   usesMusic: true
@@ -270,15 +280,17 @@ const downloadProject = async (data, progressCallback) => {
     });
     analysis = downloaded.analysis;
   } else {
-    // It's a binary blob
     blob = new Blob([data]);
-    let zip;
-    try {
-      zip = await JSZip.loadAsync(data);
-    } catch (e) {
-      // It's a Scratch 1 project, probably
-    }
-    if (zip) {
+    if (isScratch1Project(bufferView)) {
+      analysis = unknownAnalysis();
+    } else {
+      let zip;
+      try {
+        zip = await JSZip.loadAsync(data);
+      } catch (e) {
+        console.warn(e);
+        throw new Error('Cannot parse project');
+      }
       const projectDataFile = zip.file('project.json');
       const projectDataText = await projectDataFile.async('text');
       const projectData = JSON.parse(projectDataText);
@@ -288,8 +300,6 @@ const downloadProject = async (data, progressCallback) => {
       } else {
         analysis = analyzeScratch2(projectData);
       }
-    } else {
-      analysis = unknownAnalysis();
     }
   }
 
diff --git a/src/scaffolding/dropper.js b/src/scaffolding/drop-area.js
similarity index 95%
rename from src/scaffolding/dropper.js
rename to src/scaffolding/drop-area.js
index 0f23dae..b537f85 100644
--- a/src/scaffolding/dropper.js
+++ b/src/scaffolding/drop-area.js
@@ -1,7 +1,7 @@
 import styles from './style.css';
 import {readAsText} from '../common/readers';
 
-class Dropper {
+class DropArea {
   constructor (el, callback) {
     this.el = el;
     this.callback = callback;
@@ -32,4 +32,4 @@ class Dropper {
   }
 }
 
-export default Dropper;
+export default DropArea;
diff --git a/src/scaffolding/monitor.js b/src/scaffolding/monitor.js
index d47de67..35a0c15 100644
--- a/src/scaffolding/monitor.js
+++ b/src/scaffolding/monitor.js
@@ -1,5 +1,5 @@
 import ContextMenu from './context-menu';
-import Dropper from './dropper';
+import DropArea from './drop-area';
 import styles from './style.css';
 import {readAsText} from '../common/readers';
 
@@ -269,7 +269,7 @@ class ListMonitor extends Monitor {
     this.root.appendChild(this.rowsOuter);
     this.root.appendChild(this.footer);
 
-    this.dropper = new Dropper(this.rowsOuter, this.dropperCallback.bind(this));
+    this.dropper = new DropArea(this.rowsOuter, this.dropperCallback.bind(this));
 
     this.handleImport = this.handleImport.bind(this);
     this.handleExport = this.handleExport.bind(this);
@@ -315,9 +315,7 @@ class ListMonitor extends Monitor {
       const files = e.target.files;
       if (files.length === 0) return;
       const file = files[0];
-      readAsText(file).then((text) => {
-        this.import(reader.result);
-      });
+      readAsText(file).then((text) => this.import(text));
     });
     fileSelector.click();
   }
diff --git a/src/scaffolding/question.js b/src/scaffolding/question.js
index 0512ad7..05bb3c3 100644
--- a/src/scaffolding/question.js
+++ b/src/scaffolding/question.js
@@ -1,4 +1,4 @@
-import Dropper from './dropper';
+import DropArea from './drop-area';
 import styles from './style.css';
 
 class Question {
@@ -25,7 +25,7 @@ class Question {
     this.input.className = styles.questionInput;
     this.input.addEventListener('keypress', this.onkeypress.bind(this));
 
-    this.dropper = new Dropper(this.input, this.dropperCallback.bind(this));
+    this.dropper = new DropArea(this.input, this.dropperCallback.bind(this));
 
     this.submitButton = document.createElement('button');
     this.submitButton.className = styles.questionSubmitButton;
diff --git a/test/packager/download-project.test.js b/test/packager/download-project.test.js
index 859524c..fa08b36 100644
--- a/test/packager/download-project.test.js
+++ b/test/packager/download-project.test.js
@@ -60,3 +60,12 @@ test('sb', async () => {
   expect(project.blob.size).toBe(554);
   expect(project.type).toBe('blob');
 });
+
+test('invalid project', async () => {
+  try {
+    await downloadProject(readTestProject('invalid.txt'), () => {});
+  } catch (e) {
+    return;
+  }
+  throw new Error('Expected error, got success');
+});
diff --git a/test/packager/projects/invalid.txt b/test/packager/projects/invalid.txt
new file mode 100644
index 0000000..590847a
--- /dev/null
+++ b/test/packager/projects/invalid.txt
@@ -0,0 +1 @@
+I am not a valid project