Go to .
Press Ctrl+Alt+P while the viewer is active to reopen the hidden configuration window. Go to the "Graphics Runtime" tab and adjust the "Window Attributes." Alternatively, you must re-author the start picture in the Graphics Designer on the server to match a smaller resolution, or disable scaling in the Windows display settings for the application.
If the Viewer RT opens but shows a black screen or "No connection," check these local client fixes: TIA Portal: WinCC Unified Installation Problems (Fixed)
: Temporarily disable the Windows Defender Firewall on both machines to see if the download succeeds. If it does, create specific exceptions for WinCC and SQL Server processes.
Fix 4: Repairing the "Server Not Available" or Disconnection Loop
: C:\Documents and Settings\ \Application Data\Siemens\SIMATIC.WinCC\WebNavigator\Client\WinCCViewerRT.xml .
If you’re wrestling with the dreaded “WinCC Viewer RT download” issue, this review brings color, clarity, and practical fixes—served with energy and zero fluff. Below I cover symptoms, likely causes, quick checks, and step-by-step fixes so you can get your Siemens WinCC Runtime/Viewer back to smooth operation.
: Right-click on WinCCViewerRT.exe (found in ... \WebNavigator\Client\bin ) and select Run as Administrator .