Manuel,
So I'm gathering from your message that you are able to navigate to a file ending in '.txt' with the open data dialog, but nothing happens after you select it. Is that correct?
After opening a .txt file you should see another dialog titles 'Read Delimited File'. Are you using the JGR console, or the RGui console? Please enter the following into R after Deducer is loaded and send the output:
sessionInfo()
.jcall("java/lang/System","S","getProperty","java.version")
Best,
Ian