If you have used Rltool before, and have recently upgraded to version 1.4 please do the following:
you will find a file .rltoolcfg.sci (note the [dot] before the filename) which will be located, most probably in your home directory. This conflicts with the format of version 1.4. You will need to delete this file, before you can start using version 1.4.

Note that you only need  remove this file if you have been using an older version of rltool. Version 1.4 also creates its own .rltoolcfg.sci  which neednot be deleted.

Rltool searches for .rltoolcfg.sci in your present working directory EVERY TIME you load it. If you have already deleted this file once you needn't delete it every time.