“Collection was modified; enumeration operation may not execute.”
This error interrupts the gearing strategy report and all work it might have done is lost.
I wish I could give you more detail than this, but this was the extent of the error message.
I was running the Gearing Strategy on my 120 Holy Priest on Tichondrius: Arelameth.
I am using the latest client release 1076. Below are the simulation settings.