So, just updated to Android Studio 1.4 Beta 4 and having trouble building a release build. I can build a debug build fine. This is the error I get:
ExternalS
I had the same problem but with this error:
ExternalSystemException: String index out of range: -119
My problem was that in the string editor i forgot to set a default variable into my translation, after adding it, the problem was solved.
Hope it helps!