Hmm, I loaded it up on one of my toons (120 Wiz) after porting to SL and it appeared to work. At least the one Cannonball posted;
View attachment 51023
Granted, I did the quest already so it ended, but from zone in it went to Drent and tried to get the quest. I assume you have mq2nav loaded as it does require that and that you're in SL.
The fact that the error says it can't open it makes think its a corrupt download or not in the right directory somehow.
Double check it's in the right folder by right clicking on the MQ icon on the taskbar and choose the macros directory
View attachment 51024
It pulls up the folder and shows you the directory it's pointing to. Mine shown below, but I installed to a different directory
View attachment 51025
Gonna need someone with a bit more knowledge than me on this one if the above doesn't work, sorry.