So it looks like I'm going to answer my own question. I had one final inspiration: the one difference between the FM server script engine and FM Pro Adv is the account the script is running under. It turns out during the install they created a new share and did not apply the same security permissions to the folder. Hence, the system account FM Server was installed under did not have access to the share (as used in the ODBC DSN). I reinstalled FM Server 16 using the network account I have access to and it now works. Final solution is to fix the security issue and reinstall using the default system account. Hope this helps someone in the future.