Okey Dokey, I can expand that a little.
A file is to big when it's to big to fit in the limited memory in an AM/LM/HC or disk space in RPA or HC Sim. All those values are different but for the problem you reported in that RPA could not "see" the file the size of your file was not an issue. You can load a 50 megabyte wav file into RPA and it's not an issue. Of course you wouldn't be able to use a file that big as it would never fit into an AM/LM/HC but RPA can see files that big because the size of the file doesn't come into play when your browsing for files.
Yes, RPA expects a mono wav file but that does not stop it seeing the wav file if it's not mono, RPA will throw an error when you try to convert the wav file into RP format if it's not mono but it won't stop RPA from seeing it.
Yes, RPA can only see things on the C drive (stupid I know) and yes there is an issue with how many directories (folders) on the drive that RPA can display. I forget the exact number of directories that RPA can show but if that number is n and c:\temp is n+1 then RPA won't show the directory, or any others higher than n, counting alphabetically.
If your wav file is not the correct format RPA will throw errors at you letting you know what is wrong when you try to convert it. As per the manual the wav file needs to be 16 bit, 44100Hz mono. To convert your file to this format you'll need an audio editor. Audacity is a good free tool for this. If you think it's a bit beyond your skill level asking here on RPUG for someone to convert it for you is likely to elicit a response.
- Tim