diff --git a/lib/core/option.py b/lib/core/option.py
index 33ec158c3..a39989ad8 100644
--- a/lib/core/option.py
+++ b/lib/core/option.py
@@ -870,13 +870,16 @@ def _setPreprocessFunctions():
                 raise SqlmapSyntaxException("cannot import preprocess module '%s' (%s)" % (getUnicode(filename[:-3]), getSafeExString(ex)))
 
             for name, function in inspect.getmembers(module, inspect.isfunction):
-                if name == "preprocess" and inspect.getargspec(function).args and all(_ in inspect.getargspec(function).args for _ in ("req",)):
-                    found = True
+                try:
+                    if name == "preprocess" and inspect.getargspec(function).args and all(_ in inspect.getargspec(function).args for _ in ("req",)):
+                        found = True
 
-                    kb.preprocessFunctions.append(function)
-                    function.__name__ = module.__name__
+                        kb.preprocessFunctions.append(function)
+                        function.__name__ = module.__name__
 
-                    break
+                        break
+                except ValueError:  # Note: https://github.com/sqlmapproject/sqlmap/issues/4357
+                    pass
 
             if not found:
                 errMsg = "missing function 'preprocess(req)' "
@@ -1525,7 +1528,7 @@ def _createHomeDirectories():
     if conf.get("purge"):
         return
 
-    for context in "output", "history":
+    for context in ("output", "history"):
         directory = paths["SQLMAP_%s_PATH" % context.upper()]
         try:
             if not os.path.isdir(directory):
diff --git a/lib/core/settings.py b/lib/core/settings.py
index fed68f099..ca7a23534 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -18,7 +18,7 @@ from lib.core.enums import OS
 from thirdparty.six import unichr as _unichr
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.4.9.22"
+VERSION = "1.4.9.23"
 TYPE = "dev" if VERSION.count('.') > 2 and VERSION.split('.')[-1] != '0' else "stable"
 TYPE_COLORS = {"dev": 33, "stable": 90, "pip": 34}
 VERSION_STRING = "sqlmap/%s#%s" % ('.'.join(VERSION.split('.')[:-1]) if VERSION.count('.') > 2 and VERSION.split('.')[-1] == '0' else VERSION, TYPE)