Database not active or not accessible

I am using Natural v6.34, and ADABAS v6.1.4.04 in a Vista environment. Both have installed without issue, but now I get the following error when I try to run a program that accesses the database:

Database 12 is not active or not accessible.

When I look at the database in the DBA Workbench, it sure looks active to me.

Any ideas?