diff --git a/JsonPreprocessor/CJsonPreprocessor.py b/JsonPreprocessor/CJsonPreprocessor.py
index df25e68..1fa2a04 100644
--- a/JsonPreprocessor/CJsonPreprocessor.py
+++ b/JsonPreprocessor/CJsonPreprocessor.py
@@ -1635,9 +1635,11 @@ def __isAscii(sInput : str) -> bool:
         elif '${' not in sInput and not regex.match(r'^\s*\[\s*import\s*\]\s*$', sInput.lower()):
             if not oKeyChecker.keyNameChecker(sInput) and __isAscii(sInput):
                 errorMsg = oKeyChecker.errorMsg
-        elif regex.search(r'\[[^\'\[]+\'[^\']+\'\s*\]|\[\s*\'[^\']+\'[^\]]+\]', sInput) or\
-            regex.search(r'\[[^\d\]]+\d+\]|\[\d+[^\d\]]+\]', sInput):
+        elif regex.search(r'\[[^\'\[]+\'[^\']+\'\s*\]|\[\s*\'[^\']+\'[^\]]+\]', sInput) or \
+            regex.search(r'\[[^\d\[\]]+\d+\]|\[\d+[^\d\]]+\]', sInput):
             errorMsg = f"Invalid syntax: {sInput}"
+            if regex.search(r'\[\s*[\-\+]\d+\]', sInput):
+                errorMsg = f"Slicing is not supported (expression: '{sInput}')."
         elif regex.match(r'^\s*\${.+[\]}]*$', sInput):
             tmpInput = sInput
             while regex.search(r'\[[^\[\]]+\]', tmpInput):
@@ -1651,6 +1653,8 @@ def __isAscii(sInput : str) -> bool:
             errorMsg = f"Invalid key name: {sInput} - This key name must be '{correctKey}'"
         elif sInput.count('${') != sInput.count('}') or sInput.count('[') != sInput.count(']'):
             errorMsg = f"Invalid key name: {sInput} - The brackets mismatch!!!"
+        elif regex.match(r'^\s*[^\$]+\${.+$|^\s*\${.+[^}\]]\s*$', sInput):
+            errorMsg = f"Invalid key name: '{sInput}'."
         elif regex.search(r'\${[^}]*}', sInput):
             if regex.search(r'\[\s*\]', sInput):
                 errorMsg = f"Invalid key name: {sInput}. A pair of square brackets is empty!!!"
@@ -2073,7 +2077,7 @@ def __handleLastElement(sInput : str) -> str:
                                 if i==iItems:
                                     item = __handleLastElement(item)
                                 elif not regex.match(r'^[\s{]*"[^"]*"\s*$', item):
-                                    item = regex.sub('(\$.+)\s*$', '"\\1" ', item)
+                                    item = regex.sub('^\s*([^\s].+[^\s])\s*$', '"\\1" ', item)
                         while CNameMangling.STRINGVALUE.value in item:
                             if "${" in tmpList[0]:
                                 sValue = tmpList.pop(0)
diff --git a/JsonPreprocessor/JsonPreprocessor.pdf b/JsonPreprocessor/JsonPreprocessor.pdf
index b90bb01..73c717a 100644
Binary files a/JsonPreprocessor/JsonPreprocessor.pdf and b/JsonPreprocessor/JsonPreprocessor.pdf differ
diff --git a/JsonPreprocessor/version.py b/JsonPreprocessor/version.py
index 5ceb649..4db8b79 100644
--- a/JsonPreprocessor/version.py
+++ b/JsonPreprocessor/version.py
@@ -18,6 +18,6 @@
 #
 # Version and date of JsonPreprocessor
 #
-VERSION      = "0.9.1"
-VERSION_DATE = "22.5.2025"
+VERSION      = "0.9.2"
+VERSION_DATE = "5.6.2025"
 
diff --git a/packagedoc/additional_docs/History.tex b/packagedoc/additional_docs/History.tex
index a17e8bd..b3abae0 100644
--- a/packagedoc/additional_docs/History.tex
+++ b/packagedoc/additional_docs/History.tex
@@ -104,4 +104,8 @@
 \historychange{- Enhanced cyclic import detection\newline
 - Fixed bugs and updated error messages}
 
+\historyversiondate{0.9.2}{06/2025}
+\historychange{- Improved invalid key name detection\newline
+- Fixed bugs}
+
 \end{packagehistory}