No mountable file systems

I am unable to open the adobe connect download. Everytime i open it up I get the warning pop up saying that it cannot be opened due to 'no mountable file systems'. I do not know how to fix this. 

I am downloading from a Mac-book Air using OS X El Capitan. I have tried downloading from Safari and from Chrome. Nothing is working. 

I have seen that this has been a common problem for a lot of people, especially regarding the newest adobe connect update. But I cannot find an answer answer on how to sort out this problem.