Rockbox/Sansa ClipZip database initialize attempt -> "data abort" error message

[pacman]

Just installed Rockbox Version 3.13 on Sansa Clip Zip with SD card plugged in, transferred songs to the SD card with Windows 7 Explorer, fired up Rockbox, ascertained that songs play normally when accessed via the Files option, tried to access them via the Database route, got message "database is not ready...initialize now", responded with Select, Clip Zip responded immediately with "Data abort at 30FSR 0x8 (domain 0, fault address 0x745F65 pc:3004FD60 sp:3bt end" and appeared to freeze. The Clip Zip could be shut down by holding the On-off button at the top for a good 30 seconds.

What now ? What does this error message mean ? How do I get the database function to work ? I'm wondering whether Rockbox has specific requirements for database indexing of song files, e.g. that the files must be in a particular folder structure or not exceed a maximum length (some software cannot handle files if the total length of the filename plus the folder name(s) exceeds 256 bytes). 

I've searched this forum without success. Postings related to this problem seem to be all very old ones (so possibly not relevant to the RB version I have installed) or are not related to the Sansa Clip Zip (or is that not relevant ?). The error message is incomprehensible to me and I can't find an index of error message that might help me further.