You are trying to download software from Microsoft Imagine Site while using the Secure Download Manager (SDM) while on the Mac.
You get the following error message:
Not connected to the Internet. Please connect and try again. TODO Provide proper texts
You get this message, even though you are connected to the internet and able to browse...
Some of the software that is available to download from the Microsoft Imagine uses the Secure Download Manager (SDM), however, the SDM installer has not been updated and may not work with more up to date OS systems.
On Mac OS X higher than Yosemite, we have found that the SDM no longer works properly and gives this message.
Newer Microsoft Software does not seem to use SDM, but downloads directly.
Unfortunately, there is no convenient solution in order to download the software on a Mac that is running on a more recent version of Mac OS X.
Your only alternative at this time is to try and download via a different computer, most likely Windows 7 computer.
Due to Microsoft and Apple trying to encourage people to go to newer software, neither Microsoft nor Apple will make much effort in supporting older software or make it easy to get older software.
ECI will also not be able to provide much support in downloading it short of recommending downloading from a Windows 7 computer or older Mac OS X system, as our ability to get said software is also under these limitations.