Black screen during preview

When I preview the project. First ,everything seemed to be ok. However, after about two or more slides the screen turns black. Please help.

Hi Hannah,

Could you share with us the AP project file (.approj) with external data folder (if any) at so that we can check?
The data folder has the name in the form projectFileName_files. It’s located in the same folder with the project file.
If the file size is large, you can upload it to a cloud storage service like Google Drive.