Hello Vlad,

It was unintentional. The code was written using the standard Firebird install (localhost:c:\Path\To\MyDB) but I have to support both full server and embedded in my case. When I put the logic in to detect which mode my application was running in, I updated the DatabaseName and Protocol properties but forgot to change the servername (which was localhost) to be conditionally set.

This is of course ambiguous and a bug on my part, but my confusion came because the setter method changed the Protocol property that I had explicitly set to Local and changed it to TCP. This meant it then attempted to connect using the Firebird service on my PC rather than the embedded engine loaded in my process and therefore I received the above error.

All sorted now.

Thanks
Adam