Problem Debranding c905a

[aznayaka]

Configuration Error means that your missing files like customize.xml, preloaded_config.xml (Well that what I think). Without this phone can start up but you will get that error.
When you manually flash it with new FS, it seem to lose those.

So go to the Downloads at the top, find custom file, click the one you want (in this case c905custpack), then download one of them (I would choose either of the generic_america since your phone is in fs_america_red53).
After you download it use your A2uploader, click FileSystem tool then plug your phone.
Drag Customize.xml and preloaded_config.xml into the tpa/preset/custom (I think when you download the pack it will come with other stuff too so you can put them together if you want) then Shutdown FS or whatever the red text say.
That should fix the configuration error.