You used an invalid regular expression search pattern.
The following exception block, placed at the end of a method that does a regular exception search, traps for invalid search patterns and prints the Message property of the RegExSearchPatternException. You could also use RegExException, since RegExSearchPatternException is subclassed from RegExException.
Exception err As RegExSearchPatternException
RegExException, RuntimeException classes Try, Exception statements, Catch statement.