To: lemonahoy
Hello,
Thank you for the information,
To avoid the problem 
please completely uninstall AVS4YOU software from your PC. Instructions below:
1. Follow 
this link and download 
the utility that will automatically remove all AVS software components from your PC. Save the utility on your computer and launch it. 
2. Download the latest versions of the programs from 
our website.
Now install the software on your PC anew.
3. Please also enable "
Use Video buffer" option to avoid issues with black screen:
Edit > Settings > Preview > Video Rendering = Use video buffer > restart the program.
If it does not solve the issue, please contact us again.
Best regards!