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## Problem [PdfThumbnailProvider](cci:1://file:///d:/Github/PowerToys/src/modules/previewpane/PdfThumbnailProvider/PdfThumbnailProvider.cs:15:8-18:9) could fail at compile-time **and/or** produce empty or invalid thumbnails at runtime: 1. [Image](cci:1://file:///d:/Github/PowerToys/src/modules/previewpane/PdfThumbnailProvider/PdfThumbnailProvider.cs:81:8-103:9) / `Bitmap` types come from **System.Drawing**, but the namespace was missing, causing build errors in environments that don’t rely on implicit global usings. 2. After rendering the first PDF page to an in-memory stream, the stream’s cursor remained at the end. `Image.FromStream(stream.AsStream())` therefore read **zero bytes**, throwing an exception or creating an empty bitmap. ## Fix * Added explicit `using System.Drawing;`. * Added `stream.Seek(0);` right before `Image.FromStream(...)` to rewind the stream to the beginning. ```csharp using System.Drawing; // new ... page.RenderToStreamAsync(...).GetAwaiter().GetResult(); stream.Seek(0); // rewind so Image.FromStream reads data imageOfPage = Image.FromStream(stream.AsStream()); ``` ## Testing - Rebuilt the solution – compilation succeeds without missing-namespace errors. - Ran thumbnail handler against multiple PDFs; thumbnails now render correctly and no runtime exceptions are thrown. ## Impact Users regain reliable PDF thumbnail previews in Explorer, improving usability and preventing crashes or blank icons. --------- Co-authored-by: leileizhang <leilzh@microsoft.com>