Error 4.2 to switch from export to performance in 4.2.0b

Error 4.2 to switch from export to performance.... I returned to install the version 4.1.2 normal.........

I not speak inlges translator

To Image:

https://dl.dropboxusercontent.com/u/31712494/Captura%20de%20pantalla%202016-07-15%2011.32.52.png