It'll need a new build as the input plug-in is seemingly working fine but with the alt+3 aspect there's a problem with how the core is handling the look-up for filepaths ending like "nsfe::NSF,16,,,0,,0" which is already meant to be dealt with to extract it out as 'nsfe' but something is going awry which I've still to debug further (but have a simple change for that which is better to do anyway). I can't replicate the normal atf handling failing to get the metadata unless you've got those items in the local library & if so then you'll need to try refreshing them as the metadata from that is used instead of always going to the file.
[edit]
I can do it as part of a post-release update patch instead of needing to involve a complete so that'll go up in the next few days.