> And one more reason to hate error messages. Why doesn't it just state "invalid URL" or something like that when the URL supplied
> is clearly not a path but a SID?

The message

"I/O error for file %.0s"CreateFile (open)"

is badly formatted by client (Jaybird ?)

Try to attach with isql and see normal error message :

...\firebird\bin>isql.exe "not_existed_file>"
Statement failed, SQLSTATE = 08001
I/O error during "CreateFile (open)" operation for file "not_existed_file>"
-Error while trying to open file
-The filename, directory name, or volume label syntax is incorrect.

Regards,
Vlad