If you are getting a java.lang.IllegalStateException: No match found exception while using named groups in Java regular expressions, it means that the regular expression you are using did not match the input string.

Here are a few things you can check to resolve the issue:

1. Check your regular expression: Make sure that your regular expression is correctly written and that it matches the input string. If the regular expression is incorrect, it will not match the input string, and you will get the "no match found" exception.

2. Check the input string: Make sure that the input string you are using matches the regular expression. If the input string is incorrect, the regular expression will not match, and you will get the "no match found" exception.

3. Check if the named group is defined: Make sure that you have defined the named group in your regular expression. If you have not defined the named group, you will get the "no match found" exception.

4. Check if the named group is captured: Make sure that the named group is actually capturing a value from the input string. If the named group is not capturing a value, you will get the "no match found" exception.

5. Use a Matcher object: If you are using a Pattern object to match your regular expression, make sure that you are also using a Matcher object to perform the match. You can create a Matcher object using the matcher method of the Pattern object.

Here's an example of how to use named groups in a regular expression and capture their values using a Matcher object:

String input = "John Doe, 35";
Pattern pattern = Pattern.compile("(?<name>[A-Za-z ]+), (?<age>\\d+)");
Matcher matcher = pattern.matcher(input);
if (matcher.find()) {
    String name = matcher.group("name");
    int age = Integer.parseInt(matcher.group("age"));
    System.out.println("Name: " + name);
    System.out.println("Age: " + age);
} else {
    System.out.println("No match found");
}

In this example, the regular expression "(?<name>[A-Za-z ]+), (?<age>\\d+)" matches a string that starts with a name, followed by a comma and a space, and ends with an age. The (?<name>[A-Za-z ]+) and (?<age>\\d+) are named groups that capture the name and age values, respectively. The Matcher object is used to perform the match, and if a match is found, the values of the named groups are captured and printed to the console.