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.
detectable_content:number_placeholders language:response_language startend:quotation punctuation:no_comma length_constraints:number_sentences detectable_content:postscript change_case:capital_word_frequency
ta
less than
P.P.S
at least
The response must contain at least 2 placeholders represented by square brackets Please respond to me only in Tamil You need to wrap your entire response in double quotes In your response please avoid using commas Please make sure the response less than 3 sentences long please explicitly add a note starting with P.P.S Use words in all capital letters at least 1 times