#TASK-"Merge Drawings" is not working for me

I'm using SW 2012, and trying to combine a lot of individual drawings files into a single multi-sheet file.

I saw many posts about this, and how the best way is to copy and paste. However, this is something I would have to repeat every time there are some changes made to the individual drawings. Therefore I was hoping there would be a macro that could do this with a click of a couple buttons, and after going through other people's questions came across #TASK-Merge Drawings tool.

However, I can't get it work, it gives me the error "generic error (macro)"

Does anyone have any ideas to why I'm getting this error?

Thanks

SolidworksGeneral