Two questions:
Do you have the non-xml indexer installed in a 4.2.1 database on the same machine in parallel?
When do you get the error message? During install or when you try to use it?
I have also tryed to install tamino 4.4.1 and tamino 4.2.1 on the same machine, in this case when I install nonxml indexer on a 4.4.1 database I got this error:
“File ‘C:\Program Files\Software AG\Tamino\Tamino Server Extensions\Java\xne.jar’ not found”
“Server returned error code : 7149”