# The chart or app window is blank > A blank chart or window in Scalpel: WebView2 on Windows and the built-in chart fallback, graphics drivers, UI scale, and what to send support. Source: https://scalpeltrade.com/guides/fix-charts-blank Guide 13.12, Troubleshooting. Beginner, 4 min read. Checked with Scalpel 1.12.8 on 2026-10-15. By Scalpel Team. **In short:** A chart that says **No candles** has no data yet: check the IBKR connection and your market data. A chart area that stays empty with no text is a display problem: on Windows the charts run in Microsoft Edge WebView2, and if that cannot start, Scalpel switches to its built-in chart and says "Chart engine unavailable, using the native chart". A whole window that stays black or blank points at the graphics driver. On Windows, each desk's chart is drawn with TradingView's free, open-source Lightweight Charts library, in a small WebView2 window that Scalpel places over the chart pane. You need no TradingView account or subscription. On a Mac, and whenever WebView2 is unavailable, Scalpel draws the chart itself. Both show the same candles, VWAP and your stop and target lines. First, work out which of three problems you have. ## No candles The words **No candles** in the middle of the chart pane mean Scalpel has no bars for this symbol and timeframe yet. The chart itself is fine. *Screenshot: A chart pane with nothing to draw. The order bar's size lines read - for the same reason. Demo data.* - **Check the IBKR pill** in the status bar. Anything but **Connected** means no data: see [guide 13.1](https://scalpeltrade.com/guides/fix-disconnected). - **Check the desk's badge.** **NO DATA**, **DELAYED** or **STALE** point at market data permissions: see [guide 13.4](https://scalpeltrade.com/guides/fix-delayed-data). - **Try another timeframe.** Click **1m**, then back. A fresh symbol's history takes a moment to arrive. - **Check the symbol.** A mistyped or delisted ticker has no bars. Reload it from the symbol box ([guide 2.1](https://scalpeltrade.com/guides/load-symbols-and-desks)). ## Chart engine unavailable, using the native chart This orange toast appears once, top right, when WebView2 could not start. Scalpel switches every desk to its built-in chart for the rest of the session, so you keep trading with a working chart: candles, VWAP, your stop and target lines, all there. *Screenshot: The built-in chart taking over, with the toast. Demo data.* To get the WebView2 charts back: ### 1. Install or repair the WebView2 Runtime WebView2 is part of Windows 11 and comes with Windows 10 updates, but it can be missing or damaged. Download the **Evergreen WebView2 Runtime** from Microsoft's WebView2 page and run it. In Windows Settings, **Apps > Installed apps**, it is listed as **Microsoft Edge WebView2 Runtime**; if it is there, choose **Modify** then **Repair**. ### 2. Clear Scalpel's chart cache Quit Scalpel and delete the folder **%APPDATA%\scalpel\data\webview2**. It only holds the chart window's browser cache; Scalpel creates it again on the next start. Your settings are not in it. ### 3. Restart Scalpel Scalpel tries WebView2 again at every start. No toast means the WebView2 charts are back. ## The chart area is empty, with no text and no toast The WebView2 window started but cannot be seen. The usual cause is a **WGPU_BACKEND** environment variable set on your computer, often by another program or an old troubleshooting step. Scalpel draws its own window with DirectX 12 (or OpenGL as a fallback) so the chart windows show above it; a Vulkan setting hides them. Check in Windows: search for **Edit environment variables for your account**, look for **WGPU_BACKEND**, delete it, and restart Scalpel. **Tip.** You can always choose the built-in chart instead: add an environment variable named **SCALPEL_NATIVE_CHART** with the value **1** and restart Scalpel. Delete it to go back to the WebView2 charts. If the chart sits in the wrong place after you change **UI scale** in **Settings > Appearance** or move the window to a monitor with a different Windows display scale, press `Ctrl`+`0` to reset the UI scale to 100%, and restart Scalpel if it stays wrong. ## The whole window is black or blank Scalpel draws its interface on the graphics card. A window that never draws at all usually means an old or broken graphics driver. - **Update the graphics driver** from your PC maker or the chip maker (Intel, AMD or NVIDIA), then restart Windows. - **Remote desktop and virtual machines** may have no usable graphics acceleration. Run Scalpel on the physical computer. - **Send us the log.** If it still fails, post **%APPDATA%\scalpel\data\logs\scalpel.log** on Discord ([guide 12.6](https://scalpeltrade.com/guides/discord-support)) with your Windows version and graphics card. ## Questions **Why does my Scalpel chart say No candles?** There is no chart data for that symbol and timeframe yet, usually because TWS is not connected or the symbol has no live market data on your account. **Do I need a TradingView subscription for Scalpel's charts?** No. The charts use TradingView's free, open-source Lightweight Charts library, built into Scalpel. No TradingView account is involved. **Is the built-in chart worse for trading?** It draws the same candles, VWAP and your stop and target lines. It is the chart Scalpel always uses on a Mac. **What is WebView2?** Microsoft's component for showing web content inside Windows apps. Scalpel uses it to draw the desk charts on Windows.