Hey there, just joined the forums to share a problem I had and the solution to it.
Originally I was looking for any form of light encryption (just enough to keep the honest people honest), but had errors spit up with standard RMMV encryption. Which lead me to your plugin. Unfortunately, I had similar errors spit up upon completion of encryption. These errors would state missing assets, such as missing audio files or missing image files. Googling didn't help.
Finally after about an hour of troubleshooting, I just played my game and dismissed the errors, and realized: not all of the sound and image files were giving errors. That's when I realized that the files giving error are files that contained spaces in their name. For example, one file named similar to "Battle Music For Boss" wouldn't work. To solve this situation, I needed to rename all files to contain no spaces, so I changed the previous aforementioned example to something like "Battle-Music-For-Boss" or "BattleMusicForBoss".
It took so long for me to realize this as the problem because some of the first sounds (such as menu music, and UI sounds) all contained spaces in their name, so of course at first launch it appeared to me that all audio files were borked. It wasn't until deciding to proceed with playing the game and ignoring the errors that I realized not every sound file was borked.
It may seem like a pretty obvious problem to most people, but I wasn't aware that the encryption would have problems with spaces in the name. Also, upon further consideration, this was the same problem I faced with the vanilla RMMV encryption, and likely means that both this plugin and vanilla encryption require no spaces in the file name.
TLDR; Ensure there are no spaces in the file name. Doing this at an early stage in development will lead to less headache later having to track down every call of a sound effect and reassigning it to the renamed file.