I have created gantt chart with indirect function (because it pulls data from another sheet). The point is I had to do it in that way since second sheet working as database and it always changes. If someone remove row in that sheet or if it is empty, my formulas go crazy with error #!Ref and I have to change everything manualy.
I do not want to use Macro for this operation, because indirect function doing excellent job.
Excel 2013 see everything fine and chart is working like a charm, but PDF/Printer does not see exactly these Conditional formatted with Indirect function cells. I tried to remove Indirect function and it was visible on PDF/Printer which means that Indirect in combination with CF is problem.
I'd advise to rethink the way you refer to the other sheet. Perhaps you can use functions like INDEX and MATCH to get the data you need rather than using direct cell references. That way you can also sort the data wothout disrupting your references.