Why am I receiving this warning (These files exist. Overwrite?)

[stephenrjr]

I'm trying to run a Batch Converter across my source library tree to a different target, but this warning is worrisome and unexpected. From a collection with 22,000+ tracks being converted, the warning only indicates 280 overwrites. Makes me think there are some files in one of my source trees (under `secure-smj`) that have translated filename of `_` (underscore) all at the same folder level creating the overwrite warning.

How can I track this down the the cause(s) ?