The version you have installed 8.28.3 is newer, the most recent version actually, than version 8.5. Navigate to the Connections : Tools admin page and click the Export tab. Scroll to the bottom and use the Export all tool.
Hope that helps!
ps. Connections follows, somewhat, semantic versioning (like WP) which is:
major version (MV), dot, minor version (mv), dot, bug fix (bf), dot, build (bld)
Put another way:
So in this case 28 is greater than 5 which indicates newer.