"Error Retrieving Frame 0 at Time 00;00;00 From [Source], substituting frame 0"

Software version: 14.0.4

Computer: ThinkPad X1 Extreme with a GTX 1050Ti GPU and i7-8850H CPU, running Windows 10 Pro version 1909

Whenever I try to open a new project with Premiere Pro, I get the warning message "Error Retrieving Frame 0 at Time 00;00;00 From [Source], substituting frame 0". This occurs the moment a new project is created, and [Source] is some .mp4 file from the parent folder of the .prproj file (the .mp4 file that the error refers to is not consistent between projects, so that does not appear to be the problem). Even if I don't use the video file that gave the error, any media files (either sound or video) will not preview or play when editing. I feel like it is worth noting that I can successuly save the .prproj file, but when I try to close Premiere Pro normally, the entire program stops responding, and Task Manager must be used to close the program. I have unistalled 14.0.4 and ran the Premiere Pro on both 14.0.3 and 14.0.1, and had the same error message. Hopefully this can be resolved quickly and easily, as it's causing me to fall behind on YouTube uploads. Thank you!