Mariano helps with You receive “Could’n retrieve the list of available databases: The connection attempt failed” error when updating Management Reporter 2012
The Dynamics GP Blogster: You receive “Could’n retrieve the list of available databases: The connection attempt failed” error when updating Management Reporter 2012
Reporting & BISQL & DataInstall, Upgrade & Admin
Archived post from 2015. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.