Slitherine

After downloading the game and attempting to install I received this error message.
"The installer cannot install the upgrade patch because the program being upgraded may be missing or the upgrade patch updates a different version of the program"
Not sure where to go from here. I know I spent 20 bucks so far but that's about it.

Anyone have this issue or anyone know how to fix it??

Have you bought the Mega Pack?
Please note that The Battle Academy Mega Pack is a collection of all previous Battle Academy Expansions and needs the base game:
http://www.slitherine.com/games/bbc_ba_pc

That was indeed the problem. Thank you sir. Issue resolved/