"Scan directories now!" doesn't work anymore

All of a sudden the "Scan directories now!" feature in the setup doesn't work anymore. A blank screen appears and the address-bar shows: http://www.idhome.nl/phpAlbum/main.php?cmd=setup&var1=pics&var2=scan_dirs

I only uploadede some thumbnails for for .AVI and .MP3 files.
The automatic full directory scan als doesn't work anymore.

The following two warnings appear in the Error log:

Warning
08/07/24 13:57:49 array_slice() [function.array-slice]: The first argument should be an array
/var/www/html/phpAlbum/main.php (Line:980)

Warning
08/07/24 13:57:49 Invalid argument supplied for foreach()
/var/www/html/phpAlbum/main.php (Line:981)