Picard crashes with no debug output when you paste an invalid naming script.  The script which caused the crash here is:

  $firstalphachar(%artistsort%,nonalpha="#")/$swapprefix(%artist%,*prefixes="a","the")$if($eq(%musicbrainz_albumartistid%,89ad4ac3-39f7-470e-963a-56509c546377),/%album%)/%artist% - %title%