Though it has been a long time, I'm wondering whether you have fixed this problem. I met the exactly same problem and once solved.
The method is to change the registry table of windows (Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes). There you can see Helvetica. Right click and choose Modify. Change the Data from Helvetica to Arial while keeping the name as Helvetica. Restart your MATLAB to see whether it works.
You can try. It worked for me on windows 8 with R2016. However, I updated my OS to windows10 and MATLAB to R2017b recently, this problem appears again and this method won't work for this time. I don't know why and I'm still working on it. If you have any solution, please tell me.