install problem on Mac Mini Yosemite

[knibbeje]

Hi,
I was prompted to upgrade to latest version 5.1 on my Mac Mini running Yosemite. I downloaded the package, double clicked the installer and used the standard install process. The progress bar move a little bit and then froze up. It is trying to install but is stuck and it says ' writing files ' and bar is maybe just a centimeter blue (1/10 of the way done?) What is hanging it up and why? This is an upgrade, do I need to uninstall the old one? Any tricks to getting it to install?

[knibbeje]

Had to crash installer, restart. Then could load version 4.9 no problem. Then tried to run the 5.1 installer again but got stuck at same spot again.