I have just used update50 command, and upon update I have encountered with two issues not seen before (I am at week 9 now):

1) message in a pop-up window: 

    Important information regarding the Native Clipboard By default the browser doesn't allow you to use the native clipboard via menus. This means that whatever you copy via a menu needs to be pasted by the menu as well and only works in Cloud9. 
    
    To enable the native keyboard either use Command-C on Mac or Ctrl-C on Windows or for Chrome install the Cloud9 App at the Chrome store.  

2) I have downloaded the pset7.zip and pset8.zip, but when I try to open any of those I get another pop-up window:

    Can't open pset8.zip: file format unsupported

I will be grateful for support on this issue. Thank you very much!