Can't change photoshop file format when saving

Hi, I have a problem with using the photoshop CC2019. After i upgrade to macOS catalina. When i finish my work and i save my work. I can't change file format. I tried many times, still the same. I attempt to save and closed the workspace and opened again. I can't open my work file and there is a warning message showing "Could not complete your request because it is not a valid Photoshop document."