Index: gc_core/py/text.py
==================================================================
--- gc_core/py/text.py
+++ gc_core/py/text.py
@@ -56,11 +56,11 @@
 
 
 def generateParagraph (sParagraph, aGrammErrs, aSpellErrs, nWidth=100):
     "Returns a text with readable errors"
     if not sParagraph:
-        return ""
+        return ("", [])
     lGrammErrs = sorted(aGrammErrs, key=lambda d: d["nStart"])
     lSpellErrs = sorted(aSpellErrs, key=lambda d: d['nStart'])
     lErrors = sorted(lGrammErrs + lSpellErrs, key=lambda d: d["nStart"])
     for n, dErr in enumerate(lErrors, 1):
         dErr["iError"] = n