Write a Python program that takes a list of numbers as input from the user, calculates the sum of all even numbers in the list, and returns the result. The program should check if the input is valid (i.e., if it's a list of numbers), and if it's not, it should return an error message. The program should also handle exceptions gracefully and return a user-friendly error message in case of any exceptions.
change_case:english_lowercase length_constraints:number_paragraphs startend:quotation keywords:forbidden_words detectable_format:number_highlighted_sections length_constraints:number_words keywords:frequency
health
at least
less than
relationships
All letters in your response must be lower case letters Please reply in details, and include exactly 3 paragraphs. Separate the paragraphs with *** Your answer need to be wrapped in double quotes The words health cannot be in the response Make sure to highlight at least 2 sections in your answer with markdown, i.e. use *highlighted section* Keep your entire response at least 13 words or less. Mention the word "relationships" for less than 2 times