Edit Lambda trigger events not possible. Unable to validate the following destination configurations

Hi, I've seen this behavior when any of event notifications in the S3 bucket is no longer consistent (i.e one event notification configured to a lambda function that was deleted later). As a workaround, check your bucket event notification configuration in "properties" tab of Amazon S3 web console (not your Lambda Function console). Try to identify which of those are targetting non existing resources and try to fix it (delete will not work, so point them to a valid resource, for example a Lambda function that does nothing, this is temporary, just to put it in a consistent state again). Once fixed, edit the triggers in your Lambda function you were working on initially.