I can access Amazon S3 Library (screenshot:
https://snag.gy/NgU3tD.jpg), whereas I cannot upload any file to S3 bucket. I have entered the name of Amazon S3 Bucket as my default bucket. It seems that I configure the addon correctly because I can access my bucket via WordPress.
But when I upload a file, the page becomes blank (screenshot:
https://snag.gy/rD0hjO.jpg) and I got a 500 error from the broswer console. I found that the apache error log shows:
"PHP Fatal error: Uncaught InvalidArgumentException: Found 1 error while validating the input provided for the PutObject operation:\n[Bucket] is missing and is a required parameter in /var/www/html/wp-content/plugins/wplms-s3/includes/vendor/aws/aws-sdk-php/src/Api/Validator.php:65"