Status: 550 cant create directory:file exists

I am having great difficulty setting up a database in my WYSIWYG WebBuilder site. The database is showing on cpanel phpAdmin but it doesnt give me access when I upload to the web. I suspect there is a problem with the directory. There doesnt appear to be a transfer of the Mysql database to the file manager and I dont know where to check and how to do it, I thought it would have been automatic. The message I get when publishing the login panel I get: host was successfully parsed. connecting to ftp". successfully connected. Current directory is '/' setting remote folder to /public_html.. Status: 550 Cant create directory: File exists. When I tried to login on line this is the screen message I got (I hid most of the username in the following message): Warning: mysqli_connect(): Headers and client library minor version mismatch. Headers:50545 Library:50641 in /home/nar...../public_html/Members_Login.php on line 26 Warning: mysqli_connect(): (HY000/2005): Unknown MySQL server host 'localhost:3306' (0) in /home/nar....../public_html/Members_Login.php on line 26 Warning: mysqli_error() expects parameter 1 to be mysqli, boolean given in /home/nar......./public_html/Members_Login.php on line 29 Failed to connect to database server! Im hoping someone can give me some assistance. I may be a senior and not a website expert but I am determined to try and find a solution.