Subversion copy fail

Hello - I'm trying to tag the head of my svn repository and use the copy command as advised.

But I get this error message

"cannot invoke editor to get log message when non-interactive"

and this fails. I tried to turn off non-interactive mode but FB advised me this was a bad idea. More hopefully, I went to the main svn settings and turned to Quiet mode to try and suppress logging but this didn't work either. Anyone got ay ideas?

This error (which is output by subversion) usually means that a comment (commit message field) has not been provided, and is a required field.