Error with rename in flat view

I'm renaming a large amount of files spread in many folder, here is a screenshot of the general structure:
By using a button like this i can rename all file inside a folder like it's parent and it works with no problem.

Rename REGEXP PATTERN "(.*)\.(.*)" TO "{parent}.\2" AUTORENAME 

I tried to use flat view no folder and mass rename all files but it give me this error if the files are from 2 or more different folder, by selecting files inside only one it works.
I tried changing the script but with no success, is there any way to fix this problem?
Thanks in advance


Rename REGEXP PATTERN "(.*)\.(.*)" TO "{filepath|..|noterm|nopath}.\2" AUTORENAME

We have a fix for the original way you were doing things, in the next update.