By syntax checker if you mean the OK sign at the end of the expression editor, yes it is not complaining. I am not getting the desired output and the obvious i could think of was the coloring of the code.
One obvious problem that I can see in your Set Analysis is the date formatting.
Your Date field is formatted as M/D/YYYY, while your date filter in Set Analysis has the date formatted as YYYY-MM-DD. This is not going to work. In order to compare dates, they have to be formatted the same way. Removing the date filter from the first expression leads to getting some (not sure if accurate) results, as opposed to nothing.
There might be other issues too, but this one is the most obvious.
Here is another issue though, The table should show account IGV also because while Boris's sales to IGV account may be zero it's target account ID 20609 (which has target rank 1) has 3 products product id 1886, 32722 and 38732 which Boris sells.
sum of target_sales_weight
So the table should also show another row that reads as follows
Account Sales% Target Sales%
IGV 0% 0.13%
Ultimately the output should look like the following
Instead, currently it is not showing the row for IGV as shown below.
I've attached the latest qvf file which has following set analysis for Target Sales % column