According to this link :
Camera Raw plug-in | Supported cameras
the A77 II is only supported with ACR 8.5 which is not compatible with PSE11. It would need PSE12 with the latest ACR update.
The free solution is to download the Adobe DNGconverter.
That free and independent software can batch convert a whole folder of raw files to the DNG raw format that PSE11 can read.
FAQ: Will Photoshop Elements work with my camera, or Why won't my raw files open?
T find the download link, scroll down to:
What if my camera is not compatible with my version of Photoshop Elements?