Coursepress pro plugin update will not install

I had to install Coursepress pro via FTP as the automatic install via WPMUDEV would not install.

I see in my control panel there is an update for Coursepress pro plugin. Each time I try to install the update, it shows, installing update….then nothing happens, eventually the page times out. Thereafter I cannot gain access to my site for maybe 10 minutes, even after clearing cache.

Peter