Conditional Formats on Autofilter Headers

I am using code from Debra Dalgeish's website
(http://www.contextures.com/excelfiles.html , FL0018) as an example on how to
change the color of a column header if that field is filtered. The code
works fine on the spreadsheet I have saved on my personal drive, but I tried
to save this on a shared drive, and an error occurred in the following line
of code:

Range("Q3:AE3").Value = "No Conditions"

Is there some restriction in shared workbooks which would not allow this?

I have referred to the help, but I can't seem to find anything in the code
which would lead to a problem, and outside of changing some cell references,
the code is the exact same as Debra's.