Exercise: Reversing characters per word in a string

I had an exercise to write a function to reverse characters per words in a string, so if I had a string like “I go to school every day” the output would be “I og ot loohcs yreve yad”

I solved this by 2 ways, one using arrays, and the other using stacks

        public static string ReverseWords(string s, char seperator)
        {
            if (s == null)
                return "Arguments error";
            Stack<char> wordAccumlator = new Stack<char>(); // stack to hold each word
            Stack<char> textAccumlator = new Stack<char>(); //stack to hold the string after reversing words
            for (int textIterator = s.Length-1; textIterator >= 0; textIterator--)
            {
                try
                {
                    // push each character into the stack
                    wordAccumlator.Push(s[textIterator]);
                    // if charcter is the seperator, then start pushing the last word to the second stack
                    if (s[textIterator] == seperator)
                    {
                        wordAccumlator.Pop(); // to get ride of the sepertor character as we don't want to reverse it with the word
                        while (wordAccumlator.Count > 0)
                            textAccumlator.Push(wordAccumlator.Pop());
                        textAccumlator.Push(seperator); // add seperator after the word
                    }
                    else if (textIterator == 0) // at the end of the text, there is no seperator, but we need to push the last word
                    {
                        while (wordAccumlator.Count > 0)
                            textAccumlator.Push(wordAccumlator.Pop());
                    }

                }
                catch (Exception ex)
                {
                    return "An error happened, " + ex.Message;
                }
            }
            string result = string.Empty;
            while (textAccumlator.Count > 0)
                result = result + textAccumlator.Pop();
            return result;
        }

        public static string ReverseWordsWithArray(string s, char seperator)
        {
            if (s == null)
                return "Arguments error";
            int length = s.Length;
            char[] resultArray = new char[length];
            int wordLength = 0; // counter for storing the last word length
            for (int textIterator = 0; textIterator <= length; textIterator++)
            {
                try
                {
                    // we will start processing the last word only if we see the seperator or this is the end of the string
                    if (textIterator == length || s[textIterator] == seperator)
                    {
                        // if this is the end of the string, we don't 
                        if (textIterator < length)
                            resultArray[textIterator] = seperator;
                        for (int wordIterator = textIterator; wordIterator > textIterator - wordLength; wordIterator--)
                        {
                            //textIterator - wordLength represents the start location of the word
                            //(textIterator - wordIterator) represents a counter, 0, 1, 2 .. till wordLength
                            resultArray[textIterator - wordLength + (textIterator - wordIterator)] = s[wordIterator - 1];
                        }
                        wordLength = 0;
                    }
                    else
                    {
                        // we are still in the same word, increase word letters counter
                        wordLength = wordLength + 1;
                    }
                }
                catch (Exception ex)
                {
                    return "An error happened, " + ex.Message;
                }
            }
            string result = new string(resultArray);
            return result;
        }