SMALL IF Formula crashing file?! Can't figure this out!

My co-worker and I have been racking our minds over this for the last week and have no idea what's going on. A file I've been sending out every week for the last year suddenly doesn't work for everyone other than me; they open it up, change a value to toggle the output and then excel crashes. I've rebuilt the file 4 times and still it doesn't work, so it's not due to hidden names or external links. It looks like it may be due to a =SMALL(IF(),ROW()-ROW()) formula which works fine on my end and is a formula I use often that I've never had problems with (i use it in other files I send out weekly that no one has issues with).



Does anyone have any ideas why this would occur? I've attached the file after removing any confidential info but it likely will not work for you. When people change cell D5 to 101-129 it crashes. The formula in question is : =IF($A7>$A$5,"",SMALL(IF(Data!$B$6:$B$511=$D$5,Data!$C$6:$C$511),ROW($C7)-ROW($C$6)))