title: Fatal error on R (3.6.1) with RQDA library
body: <p>R 3.6.1 Crashes when I load RQDA library on macOS 10.14.5.
  I get the following Traceback :</p>
  
  <blockquote>
    <p>library(RQDA)
    Loading required package: RSQLite
    Loading required package: gWidgetsRGtk2
    Loading required package: RGtk2
    Loading required package: gWidgets
    Loading required package: cairoDevice
    Loading required package: DBI</p>
  </blockquote>
  
  <p>Use 'RQDA()' to start the programme.</p>
  
  <p><strong>* caught segfault *</strong>
  address 0x0, cause 'memory not mapped'</p>
  
  <p>Traceback:
   1: .RGtkCall("S_gtk_tree_store_set_value", object, iter, column,     value, PACKAGE = "RGtk2")
   2: method(obj, ...)
   3: store$SetValue(iter$iter, column = 0, items[j, 1])
   4: <code>.leftBracket&lt;-</code>(<code>*tmp*</code>, x@toolkit, i, j, ..., value = value)
   5: <code>.leftBracket&lt;-</code>(<code>*tmp*</code>, x@toolkit, i, j, ..., value = value)
   6: <code>[&lt;-</code>(<code>*tmp*</code>, , value = list(items = c("blue", "white", "aliceblue",</p>
  
  <p>Appreciate any help</p>
  
  <p>ACSF</p>