Hi @Trax21,
Thanks for getting in touch!
Let's solve that error message with the .wav files.
Do you get the same error with newer files, or different file extensions?
Also, when you download the files, do they display properly on your device?
You can try clearing the browser's cache. That will usually solve a temporary error like that, but in case it's related to browser settings or plug-ins, trying in a different browser altogether, or in a incognito/private mode, helps to narrow down on the cause.
Keep me posted on what you find!