Okay, I figured out what was going on. My file path was too long. This was my file path to where the soundvoltex.dll was:
"C:\Users\User\Desktop\SDVX Teknoparrot Version\Sound Voltex Exceed Gear (V-M's)\Sound Voltex Exceed Gear\SDVXEG (KFC-2023042500)\contents\soundvoltex.dll"
Some files that are being loaded by the game may have paths that exceed the 256 character limit of file paths in Windows, causing the error. I solved this issue by moving the 'SDVXEG' folder to the Desktop or by shortening any folder name in the path above.