Before what? Before you installed a newer version of Shotcut? Or before something else?
If the previous version of Shotcut works well on your system, you can keep using that. Sometimes people think that a Shotcut update has broken something so they go to an older version only to find that it doesn’t work any better. Eventually they find out that something else has changed on their system. Or that they started using more challenging source files and did not realize it. Or maybe the video mode has been changed to a higher resolution.
If you are unable to determine what changed for you, there are many techniques available to improve the performance:
- Preview Scaling
- Proxy Editing
- The “Convert” button in the clip properties panel can make the source file more friendly for editing.