Notepad++ is free and has a "find in files" feature, I don't think windows search is really designed to look into files for strings, never used it for that myself in any case. :P

Btw very unhappy that major interface changes aren't officially announced in a compilation on the official forums, even the MVP aren't really doing it and I reckon if you are a Interface/addons MVP you'd have to focus and try report API changes and such between major patches. I don't know, maybe I demand too much. :)

You could just get on the PTR yourself and see if your addons broked. It's not that hard to do.

Did they end up fixing the Cata Beta > PTR bug?

yes

in fact they fixed it during 4.1 ptr toward end of it.