MVC - FIx error - Index and length must refer to a location within the string

Index and length must refer to a location within the string.
Parameter name: length

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To fix it replace
            string test = "abc";
            test = test.Substring(0, 5);
with

string test = "abc";
            int StringLength = test.Trim().Length > 5 ? 5 : test.Trim().Length;
            test = test.Substring(0, StringLength);