diff --git a/arduino-ide-extension/src/browser/create/create-fs-provider.ts b/arduino-ide-extension/src/browser/create/create-fs-provider.ts
index 231d5f04..db1d7b0f 100644
--- a/arduino-ide-extension/src/browser/create/create-fs-provider.ts
+++ b/arduino-ide-extension/src/browser/create/create-fs-provider.ts
@@ -104,9 +104,9 @@ export class CreateFsProvider
       let errToRethrow = err;
       // Not Found (Create API) errors must be remapped to VS Code filesystem provider specific errors
       // https://code.visualstudio.com/api/references/vscode-api#FileSystemError
-      if (isNotFound(err)) {
+      if (isNotFound(errToRethrow)) {
         errToRethrow = createFileSystemProviderError(
-          err,
+          errToRethrow,
           FileSystemProviderErrorCode.FileNotFound
         );
       }
diff --git a/arduino-ide-extension/src/browser/widgets/cloud-sketchbook/cloud-sketchbook-tree.ts b/arduino-ide-extension/src/browser/widgets/cloud-sketchbook/cloud-sketchbook-tree.ts
index ddb805a6..09b4ced7 100644
--- a/arduino-ide-extension/src/browser/widgets/cloud-sketchbook/cloud-sketchbook-tree.ts
+++ b/arduino-ide-extension/src/browser/widgets/cloud-sketchbook/cloud-sketchbook-tree.ts
@@ -391,9 +391,10 @@ export class CloudSketchbookTree extends SketchbookTree {
     const { filesToWrite, filesToDelete } = await this.treeDiff(source, dest);
     // Sort by the URIs. The shortest comes first. It's to ensure creating the parent folder for nested resources, for example.
     // When sorting the URIs, it does not matter whether on source or dest, only the URI path and its length matters; they're the same for a source+dest pair
-    filesToWrite.sort(
-      (left, right) =>
-        left.source.path.toString().length - right.source.path.toString().length
+    const uriPathLengthComparator = (left: URI, right: URI) =>
+      left.path.toString().length - right.path.toString().length;
+    filesToWrite.sort((left, right) =>
+      uriPathLengthComparator(left.source, right.source)
     );
     for (const { source, dest } of filesToWrite) {
       const stat = await this.fileService.resolve(source);
@@ -405,11 +406,11 @@ export class CloudSketchbookTree extends SketchbookTree {
       }
     }
 
-    await Promise.all(
-      filesToDelete.map((file) =>
-        this.fileService.delete(file, { recursive: true })
-      )
-    );
+    // Longes URI paths come first to delete the most nested ones first.
+    filesToDelete.sort(uriPathLengthComparator).reverse();
+    for (const resource of filesToDelete) {
+      await this.fileService.delete(resource, { recursive: true });
+    }
   }
 
   override async resolveChildren(