Compojoom installer can't go past the 2nd step in the Hotposts Pro installation wizard.
Hotspots Core 3.7.8 was installed previously and after entering the download ID, as per instructions, I uploaded the Compojoom installer component in order to add the Pro version to my current instance.

During the installation process I get the warning you can see in my second attachment to this post

Needless to say, Joomla can update any other extension flawlessly and cURL is enabled.

From PHP sysinfo

curl
cURL support enabled
cURL Information 7.37.1