I installed both, Matlab 2014b and 2015a.
2015a does not start at all. It prompts an error message, saying that libmwregexp.dll is either not for usage with Windows or damaged.
2014b does start, but prompts an error message, saying that it can't load hgbuiltins.dll
Im not sure if both errors belong together but if someone of you may help me to get one of them solved i would be very thankfull.
best regards Raphael
System: Windows 8.1 , 64 bit Lenovo Yoga 2.