In PS CC the save for web option is greyed out. The image is in 8 bit modus. I already deleted the preferences file, but the option remains greyed out. Also starting a new image leaves a greyed out option.
The mode was just 8bit RGB. We had this problem with all our files. We couldn't find a soluition and reinstalled the entire CC download. That solved the problem. Most likely a part was missing. Is it possible to reinstall only the plugin in future? It takes a long while to download the complete CC suite again and install it.