IBConsole checks for non-empty path part of every file name specified, including database and backup file names.
This is not correct, as in case of Linux remote server paths don't follow Windows conventions (e.g. slashes / instead of baskslashes \), so the correct path like /home/someuser/somefile.gbk raises an error message.
This is probably fixed in the new version of the source files (as I checked in CVS repository) - the bug was found in build 315.