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.
length_constraints:nth_paragraph_first_word keywords:frequency length_constraints:number_sentences detectable_format:number_bullet_lists detectable_format:multiple_sections startend:quotation punctuation:no_comma
Stuart
less than
Stuart
less than
SECTION
answer exactly 4 paragraphs. Use 2 new lines to separate paragraphs. Start the first paragraph with the word "Stuart" reply should include the word "Stuart" less than 2 times The number of sentences in your response should be less than 3 Make sure the answer contains exactly 2 bullet points in markdown format Your response must contain 3 sections, mark the beginning of each section with SECTION X Please wrap your entire reply with double quotation marks You are not allowed to use any commas in your response