Sometimes all platform's settings need to be reset to default. To do this, close the platform, Right-click on Quantower icon and select Open File Location from the context menu.
A folder with the main files of the latest (installed) version of the program will open. Go to the main folder of the platform.
Rename the Settings folder (for example, Settings1 or Settings_old). After you rename the folder, run the platform. The new Settings folder will automatically appear with default settings.