The biggest limitation with the Minecraft server application is the lack of support for multi-threading. In short, this prevents the Minecraft server from taking advantage of more than a single core of the CPU. Due to this limitation, choosing a CPU with more cores won’t give you any performance benefits or support for additional players. To maximize performance a CPU with a high clock speed and less cores will yield better results than a CPU with a lower clock speed and more cores.
I simply changed the file location. My MP4 file was initially in the download folder, but when I moved it to my work folder, the problem was solved. It seems that the downloader wasn't supported for editing in Photoshop.
The only thing that helped me solve this problem is moving the video file to my dekstop. Before, I was trying to open a file located within OneDrive and Photoshop could not open it.