Next one:

Why am I getting this error when I try to open a third session in
design-time?

And what is the purpose of the LicensedSessions property in TEDBEngine?
When I try to set it to anything higher than 2, it just reverts to 2.

Documentation says "Use the LicensedConnections property to specify the
maximum number of licensed sessions allowed to access the configuration
file specified by the ConfigPath, ConfigName, and ConfigExtension
properties."

Why only 2? I'm using threads and certainly need more than 2.

Upgraded to 2.08 build 3. Problem solved.

Since it was blocked at 2, I'm guessing I was on a trial version, which
I never deliberately downloaded, but I do remember that there were site
problems at Elevate when I purchased, so I'm blaming it on confusion.

I'll be back, however!