[Chen]

Thanks for the quick reply.
This might well be what happened - i imported some attachments from the GMail app. This leads to an message that the running instance needs to be closed for security reasons. Pressed OK, no harm in restarting MSP...
One of the imports was a little weird, as i could not find the imported song afterwards in the song list. I thought i inadvertendly pressed cancel instead of OK, so i just retried the import. This time MSP alerted that the file was already there. I choose "replace" (or similar, i do not remember the exact phrase) and now then the song _was_ in the list. Probably around that time i started to get the "unable to load file: /" message.

After rebooting the device, the message seems to be gone. (i should have tried that first, sorry...!)