diff --git a/GDJS/Runtime/ResourceLoader.ts b/GDJS/Runtime/ResourceLoader.ts
index 0bb1ee9e4046..b056954c21ee 100644
--- a/GDJS/Runtime/ResourceLoader.ts
+++ b/GDJS/Runtime/ResourceLoader.ts
@@ -29,6 +29,19 @@ namespace gdjs {
     );
   };
 
+  const encodeLocalResourceUrl = (url: string): string => {
+    if (
+      url.startsWith('http://') ||
+      url.startsWith('https://') ||
+      url.startsWith('data:') ||
+      url.startsWith('blob:')
+    ) {
+      return url;
+    }
+
+    return encodeURI(url).replace(/#/g, '%23');
+  };
+
   /**
    * A task of pre-loading resources used by a scene.
    *
@@ -617,6 +630,8 @@ namespace gdjs {
      * the resource (this can be for example a token needed to access the resource).
      */
     getFullUrl(url: string) {
+      url = encodeLocalResourceUrl(url);
+
       if (this._runtimeGame.isInGameEdition()) {
         // Avoid adding cache burst to URLs which are assumed to be immutable files,
         // to avoid costly useless requests each time the game is hot-reloaded.
diff --git a/newIDE/app/scripts/import-libGD.js b/newIDE/app/scripts/import-libGD.js
index 2accaaeac2f9..7e346637ff92 100644
--- a/newIDE/app/scripts/import-libGD.js
+++ b/newIDE/app/scripts/import-libGD.js
@@ -66,17 +66,28 @@ if (shell.test('-f', path.join(sourceDirectory, 'libGD.js'))) {
     return branch;
   };
 
-  // Try to download libGD.js from a specific commit on the current branch
-  const downloadCommitLibGdJs = (branch, gitRef) =>
+  const getHashFromGitRef = gitRef => {
+    const hashShellString = shell.exec(`git rev-parse "${gitRef}"`, {
+      silent: true,
+    });
+    const hash = (hashShellString.stdout || 'unknown-hash').trim();
+
+    if (hashShellString.stderr || hashShellString.code) {
+      shell.echo(`⚠️ Can't find the hash of the associated commit.`);
+      return null;
+    }
+
+    return hash;
+  };
+
+  // Try to download libGD.js from a specific commit on the inferred branch.
+  const downloadCommitLibGdJs = gitRef =>
     new Promise((resolve, reject) => {
       shell.echo(`ℹ️ Trying to download libGD.js for ${gitRef}.`);
 
-      var hashShellString = shell.exec(`git rev-parse "${gitRef}"`, {
-        silent: true,
-      });
-      const hash = (hashShellString.stdout || 'unknown-hash').trim();
+      const hash = getHashFromGitRef(gitRef);
       const branch = getBranchFromGitRef(gitRef);
-      if (hashShellString.stderr || hashShellString.code || !branch) {
+      if (!hash || !branch) {
         shell.echo(
           `⚠️ Can't find the hash or branch of the associated commit.`
         );
@@ -91,6 +102,23 @@ if (shell.test('-f', path.join(sourceDirectory, 'libGD.js'))) {
       );
     });
 
+  const downloadMasterCommitLibGdJs = gitRef =>
+    new Promise((resolve, reject) => {
+      shell.echo(`ℹ️ Trying to download libGD.js for ${gitRef} from master.`);
+
+      const hash = getHashFromGitRef(gitRef);
+      if (!hash) {
+        reject();
+        return;
+      }
+
+      resolve(
+        downloadLibGdJs(
+          `https://s3.amazonaws.com/gdevelop-gdevelop.js/master/commit/${hash}`
+        )
+      );
+    });
+
   // Try to download libGD.js from the latest version built for master branch.
   const downloadBranchLatestLibGdJs = branchName => {
     shell.echo(
@@ -151,48 +179,55 @@ if (shell.test('-f', path.join(sourceDirectory, 'libGD.js'))) {
   };
 
   const branch = getBranchFromGitRef('HEAD');
+  const downloadCommitLibGdJsWithMasterFallback = gitRef =>
+    downloadCommitLibGdJs(gitRef).catch(() =>
+      downloadMasterCommitLibGdJs(gitRef)
+    );
+  const tryDownloadInOrder = downloaders =>
+    downloaders.reduce(
+      (previousDownload, download) => previousDownload.catch(() => download()),
+      Promise.reject()
+    );
 
   // Try to download the latest libGD.js, fallback to previous or master ones
   // if not found (including different parents, for handling of merge commits).
-  downloadCommitLibGdJs(branch, 'HEAD').then(onLibGdJsDownloaded, () => {
-    // Force the exact version of GDevelop.js to be downloaded for AppVeyor - because
-    // this means we build the app and we don't want to risk mismatch (Core C++ not up to date
-    // with the IDE JavaScript).
-    if (process.env.APPVEYOR || process.env.REQUIRES_EXACT_LIBGD_JS_VERSION) {
-      shell.echo(
-        `❌ Can't download the exact required version of libGD.js - check it was built by CircleCI before running this CI.`
-      );
-      shell.echo(
-        `ℹ️ See the pipeline on https://app.circleci.com/pipelines/github/4ian/GDevelop.`
-      );
-      shell.exit(1);
-    }
+  downloadCommitLibGdJsWithMasterFallback('HEAD').then(
+    onLibGdJsDownloaded,
+    () => {
+      // Force the exact version of GDevelop.js to be downloaded for AppVeyor - because
+      // this means we build the app and we don't want to risk mismatch (Core C++ not up to date
+      // with the IDE JavaScript).
+      if (process.env.APPVEYOR || process.env.REQUIRES_EXACT_LIBGD_JS_VERSION) {
+        shell.echo(
+          `❌ Can't download the exact required version of libGD.js - check it was built by CircleCI before running this CI.`
+        );
+        shell.echo(
+          `ℹ️ See the pipeline on https://app.circleci.com/pipelines/github/4ian/GDevelop.`
+        );
+        shell.exit(1);
+      }
 
-    downloadCommitLibGdJs(branch, 'HEAD~1').then(onLibGdJsDownloaded, () =>
-      downloadCommitLibGdJs(branch, 'HEAD~2').then(onLibGdJsDownloaded, () =>
-        downloadCommitLibGdJs(branch, 'HEAD~3').then(onLibGdJsDownloaded, () =>
-          downloadBranchLatestLibGdJs(branch).then(onLibGdJsDownloaded, () =>
-            downloadBranchLatestLibGdJs('master').then(
-              onLibGdJsDownloaded,
-              () => {
-                if (alreadyHasLibGdJs) {
-                  shell.echo(
-                    `ℹ️ Can't download any version of libGD.js, assuming you can go ahead with the existing one.`
-                  );
-                  shell.exit(0);
-                  return;
-                } else {
-                  shell.echo(
-                    `❌ Can't download any version of libGD.js, please check your internet connection.`
-                  );
-                  shell.exit(1);
-                  return;
-                }
-              }
-            )
-          )
-        )
-      )
-    );
-  });
+      tryDownloadInOrder([
+        () => downloadCommitLibGdJsWithMasterFallback('HEAD~1'),
+        () => downloadCommitLibGdJsWithMasterFallback('HEAD~2'),
+        () => downloadCommitLibGdJsWithMasterFallback('HEAD~3'),
+        () => downloadBranchLatestLibGdJs(branch),
+        () => downloadBranchLatestLibGdJs('master'),
+      ]).then(onLibGdJsDownloaded, () => {
+        if (alreadyHasLibGdJs) {
+          shell.echo(
+            `ℹ️ Can't download any version of libGD.js, assuming you can go ahead with the existing one.`
+          );
+          shell.exit(0);
+          return;
+        } else {
+          shell.echo(
+            `❌ Can't download any version of libGD.js, please check your internet connection.`
+          );
+          shell.exit(1);
+          return;
+        }
+      });
+    }
+  );
 }
diff --git a/newIDE/app/src/ResourcesList/ResourceUrlEncoding.spec.js b/newIDE/app/src/ResourcesList/ResourceUrlEncoding.spec.js
new file mode 100644
index 000000000000..c41d3cdbd5ea
--- /dev/null
+++ b/newIDE/app/src/ResourcesList/ResourceUrlEncoding.spec.js
@@ -0,0 +1,60 @@
+// @flow
+import ResourcesLoader from '../ResourcesLoader';
+
+jest.mock('../Utils/OptionalRequire');
+jest.mock('../Utils/CrossOrigin', () => ({
+  addGDevelopResourceTokenIfRequired: url => url,
+}));
+
+describe('ResourceUrlEncoding', () => {
+  let dateNowSpy;
+
+  const makeProject = (ptr: number): any => ({
+    ptr,
+    getProjectFile: () => 'E:\\GDevelop\\Weekend Jam #1\\game.json',
+    getResourcesManager: () => ({
+      hasResource: () => true,
+      getResource: () => ({
+        getFile: () => 'Parts/hero #1.png',
+      }),
+    }),
+  });
+
+  beforeEach(() => {
+    ResourcesLoader.burstAllUrlsCache();
+    dateNowSpy = jest.spyOn(Date, 'now').mockReturnValue(1234);
+  });
+
+  afterEach(() => {
+    dateNowSpy.mockRestore();
+  });
+
+  it('encodes hashes in local resource urls', () => {
+    const project = makeProject(1);
+
+    const fullUrl = ResourcesLoader.getResourceFullUrl(
+      project,
+      'Parts/hero #1.png',
+      { disableCacheBurst: true }
+    );
+
+    expect(fullUrl).toContain('%23');
+    expect(fullUrl).not.toContain('#');
+    expect(fullUrl).not.toContain('?cache=');
+  });
+
+  it('adds cache busting after the encoded local resource url', () => {
+    const project = makeProject(2);
+
+    const fullUrl = ResourcesLoader.getResourceFullUrl(
+      project,
+      'Parts/hero #1.png',
+      {}
+    );
+
+    expect(fullUrl).toContain('%23');
+    expect(fullUrl).not.toContain('#');
+    expect(fullUrl).toContain('?cache=1234');
+    expect(fullUrl.indexOf('%23')).toBeLessThan(fullUrl.indexOf('?cache=1234'));
+  });
+});
diff --git a/newIDE/app/src/ResourcesList/ResourceUtils.js b/newIDE/app/src/ResourcesList/ResourceUtils.js
index f98922d7dff7..a26283384868 100644
--- a/newIDE/app/src/ResourcesList/ResourceUtils.js
+++ b/newIDE/app/src/ResourcesList/ResourceUtils.js
@@ -5,6 +5,7 @@ import newNameGenerator from '../Utils/NewNameGenerator';
 import { toNewGdMapStringString } from '../Utils/MapStringString';
 const fs = optionalRequire('fs');
 const path = optionalRequire('path');
+const url = optionalRequire('url');
 const gd: libGDevelop = global.gd;
 
 export const createOrUpdateResource = (
@@ -39,7 +40,7 @@ export const getLocalResourceFullPath = (
     project,
     resourceName,
     {}
-  ).substring(7 /* Remove "file://" from the URL to get a local path */);
+  );
 
   if (resourcePath.indexOf('?cache=') !== -1) {
     // Remove, if needed, the cache bursting argument from the URL.
@@ -48,7 +49,14 @@ export const getLocalResourceFullPath = (
       resourcePath.lastIndexOf('?cache=')
     );
   }
-  return resourcePath;
+
+  if (resourcePath.startsWith('file://') && url && url.fileURLToPath) {
+    return url.fileURLToPath(resourcePath);
+  }
+
+  return resourcePath.substring(
+    7 /* Remove "file://" from the URL to get a local path */
+  );
 };
 
 export const isPathInProjectFolder = (
diff --git a/newIDE/app/src/ResourcesList/ResourceUtils.spec.js b/newIDE/app/src/ResourcesList/ResourceUtils.spec.js
index 23cbabe8c320..2732485cfcdf 100644
--- a/newIDE/app/src/ResourcesList/ResourceUtils.spec.js
+++ b/newIDE/app/src/ResourcesList/ResourceUtils.spec.js
@@ -1,9 +1,17 @@
 // @flow
 import {
+  getLocalResourceFullPath,
   parseLocalFilePathOrExtensionFromMetadata,
   renameResourcesInProject,
   updateResourceJsonMetadata,
 } from './ResourceUtils';
+jest.mock('../ResourcesLoader', () => ({
+  __esModule: true,
+  default: {
+    getResourceFullUrl: jest.fn(),
+  },
+}));
+const ResourcesLoader = require('../ResourcesLoader').default;
 const gd: libGDevelop = global.gd;
 
 const addNewAnimationWithImageToSpriteObject = (
@@ -22,6 +30,22 @@ const addNewAnimationWithImageToSpriteObject = (
 };
 
 describe('ResourceUtils', () => {
+  beforeEach(() => {
+    ResourcesLoader.getResourceFullUrl.mockReset();
+  });
+
+  it('can decode an encoded local file URL', () => {
+    const project: any = {};
+    ResourcesLoader.getResourceFullUrl.mockReturnValue(
+      'file:///E:/GDevelop/Weekend%20Jam%20%231/Parts/hero%20%231.png?cache=1234'
+    );
+
+    expect([
+      'E:\\GDevelop\\Weekend Jam #1\\Parts\\hero #1.png',
+      '/E:/GDevelop/Weekend Jam #1/Parts/hero #1.png',
+    ]).toContain(getLocalResourceFullPath(project, 'hero'));
+  });
+
   it('can rename a resource in the whole project', () => {
     const project = gd.ProjectHelper.createNewGDJSProject();
 
diff --git a/newIDE/app/src/ResourcesLoader/index.js b/newIDE/app/src/ResourcesLoader/index.js
index 43f2d79d6d80..f51121e4ef6a 100644
--- a/newIDE/app/src/ResourcesLoader/index.js
+++ b/newIDE/app/src/ResourcesLoader/index.js
@@ -3,6 +3,7 @@ import { addGDevelopResourceTokenIfRequired } from '../Utils/CrossOrigin';
 import optionalRequire from '../Utils/OptionalRequire';
 const electron = optionalRequire('electron');
 const path = optionalRequire('path');
+const url = optionalRequire('url');
 
 class UrlsCache {
   projectCache: { [number]: { [string]: string } } = {};
@@ -132,15 +133,17 @@ export default class ResourcesLoader {
       // Support local filesystem with Electron
       const file = project.getProjectFile();
       const projectPath = path.dirname(file);
-      const resourceAbsolutePath = path
-        .resolve(projectPath, urlOrFilename)
-        .replace(/\\/g, '/');
+      const resourceAbsolutePath = path.resolve(projectPath, urlOrFilename);
+      const resourceFileUrl =
+        url && url.pathToFileURL
+          ? url.pathToFileURL(resourceAbsolutePath).toString()
+          : 'file://' + resourceAbsolutePath.replace(/\\/g, '/');
 
       console.info('Caching resolved local filename:', resourceAbsolutePath);
       return this._cache.cacheLocalFileUrl(
         project,
         urlOrFilename,
-        'file://' + resourceAbsolutePath,
+        resourceFileUrl,
         !!disableCacheBurst
       );
     }
diff --git a/newIDE/app/src/Utils/__mocks__/OptionalRequire.js b/newIDE/app/src/Utils/__mocks__/OptionalRequire.js
index 73a2a6ff20a1..490e855186c1 100644
--- a/newIDE/app/src/Utils/__mocks__/OptionalRequire.js
+++ b/newIDE/app/src/Utils/__mocks__/OptionalRequire.js
@@ -45,6 +45,9 @@ const mockOptionalRequire = jest.fn(
     if (moduleName === 'path') {
       return path;
     }
+    if (moduleName === 'url') {
+      return require('url');
+    }
     if (moduleName === 'os') {
       return mockOs;
     }