Are you seeing any or logs in the WinCC "Diagnosis" folder that I can help you interpret?
Ensure there are no spaces, dots, or special characters (like @, #, %) in the folder names. 3. Reset the WinCC Project A Basic Application Could Not Be Started Wincc 7.5
Long file paths or special characters in the project folder name. Are you seeing any or logs in the
WinCC requires the logged-in Windows user to be a member of specific local groups. This is the #1 fix for "Basic Application" errors. Right-click (or My Computer) and select Manage . Navigate to Local Users and Groups > Groups . Ensure your user account is added to: SIMATIC HMI SIMATIC HMI Viewer (if applicable) Administrators Reset the WinCC Project Long file paths or
WinCC relies heavily on Microsoft SQL Server; if the instance is stopped or the database is detached, the application won't start.
Open the (found in the Siemens folder in the Start menu).