Make sure to add all files to the bundle

package.json

@@ -19,10 +19,9 @@
     "appId": "io.vikunja.desktop",
     "productName": "Vikunja Desktop",
     "files": [
-      "./frontend/",
+      "./frontend/**/*",
       "./src/index.js"
     ],
-    "asar": false,
     "linux": {
       "target": [
         "deb",
@@ -55,6 +54,7 @@
   },
   "devDependencies": {
     "@electron-forge/cli": "6.0.0-beta.52",
+    "asar": "^3.0.3",
     "electron": "9.1.0",
     "electron-builder": "^22.8.1"
   }

yarn.lock

@@ -453,7 +453,7 @@ array-find-index@^1.0.1:
   resolved "https://registry.yarnpkg.com/array-find-index/-/array-find-index-1.0.2.tgz#df010aa1287e164bbda6f9723b0a96a1ec4187a1"
   integrity sha1-3wEKoSh+Fku9pvlyOwqWoexBh6E=
 
-asar@^3.0.0:
+asar@^3.0.0, asar@^3.0.3:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/asar/-/asar-3.0.3.tgz#1fef03c2d6d2de0cbad138788e4f7ae03b129c7b"
   integrity sha512-k7zd+KoR+n8pl71PvgElcoKHrVNiSXtw7odKbyNpmgKe7EGRF9Pnu3uLOukD37EvavKwVFxOUpqXTIZC5B5Pmw==