I am having problems with the EXTENSIONS MANAGER on Mac OSX 10.11.1 - It fails to install ANY extension from the EXCHANGE with the error "please make sure the manifest.xml is valid..." This is a new Mac Pro (the ice bucket Mac =) I have been on phone support - they had no ideas and sent me to chat where I had to answer the same question three times and then get transferred to another chat in a different department and wait more -- so I came here, which is probably what i should have done in the first place. Any advice greatly appreciated.
