Hi there,
Simply remove ", stroke color:{class:no color info}" from your script and it will work.
Also, when confronted to such a situation, break up your properties to help you see which member is causing the problem:
001 tell application "Adobe Illustrator"
002 tell document 1
003 activate
004 --return properties of every path item
005 set ruler origin to {0, 0}
006 set zoom of view 1 to 0.89
007 set theProps to {}
008 set theProps to theProps & {position:{282.9570703125, 232.595703125}}
009 set theProps to theProps & {name:"theStump"}
010 set theProps to theProps & {height:23.5}
011 set theProps to theProps & {width:43.0}
012 set theProps to theProps & {filled:true}
013 set theProps to theProps & {fill color:{class:CMYK color info, cyan:25.0, magenta:42.0, yellow:100.0, black:37.0}}
014 set theProps to theProps & {stroked:false}
015 set theProps to theProps & {stroke color:{class:no color info}}
016 set theStump to make new rectangle with properties theProps
017 end tell
018 end tell
Then, it is just a matter of commenting out lines between lines
008 thru
015 to find out where this is going wrong.