Greplace.vim not loading buffers

Greplace.vim not loading buffers

I'm attempting to use Greplace for project wide find and replace but am
having trouble in the final steps.
I start with:
:Gsearch mypattern *
Which successfully opens a buffer that lists all the files and the
matches. I then perform:
:%s/mypattern/newpattern/g
Which replaces all the instances within the Gsearch buffer. It's now that
I have trouble, when I perform:
Greplace
I am now prompted whether I want to make the changes, to which I answer
with y. At which point each file should be loading in a buffer, changes
made and ready for me to :wall, but that never happens. The Gsearch buffer
remains, no others load and no changes have been made to any file.
Anyone know what I am doing wrong?