lit 24/7 in exclusion style string. josm error

[Allroads]

Josm gives a warning.
org.openstreetmap.josm.gui.mappaint.mapcss.parsergen.ParseException: Encountered "" at line 1592, column 34.

line 1592:

way|z18-["highway"]["lit"]["lit"!~/^(yes|no|24/7|sunset-sunrise|automatic)$/]::highway_lit_layer { 

this |24/7| gives the problem error josm in the exclusion string

way|z18-["highway"]["lit"="yes"]::highway_lit_layer { 
repeat-image: highway-lit-yes.svg;
}	
way|z18-["highway"]["lit"="no"]::highway_lit_layer { 
repeat-image: highway-lit-no.svg;
}
way|z18-["highway"]["lit"="24/7"]::highway_lit_layer { 
repeat-image: highway-lit-247.svg;
}
way|z18-["highway"]["lit"="sunset-sunrise"]::highway_lit_layer { 
repeat-image: highway-lit-sunset-sunrise.svg;
}
way|z18-["highway"]["lit"="automatic"]::highway_lit_layer { 
repeat-image: highway-lit-automatic.svg;
}
/* Last lit tag Else. PROBLEM with 24/7 */
way|z18-["highway"]["lit"]["lit"!~/^(yes|no|24/7|sunset-sunrise|automatic)$/]::highway_lit_layer { 
repeat-image: highway-lit-else.svg;
}

The highway-lit-247.svg is visible. When I leave out last lit tag lines, to show else icon.

This works with the 24/7 and the " "

way|z18-["highway"]["lit"="24/7"]::highway_lit_layer { 
repeat-image: highway-lit-247.svg;