Steps to resolve this issue;
1. First change the FTP user name to default as specified in welcome mail.
2. Then check whether the customer has enabled HOT PROTECTION URL, if yes disable it.
3. Then login to remote desktop >> open client lists >> open the particular domain name >> remove SECURITY file
4. Login to plesk admin >> select particular domain name >> click Check permissions
5. It will take around 2-3 minutes to complete this task.
After this remove your browser cache, cookies and try again.
If still it doesn’t open follow the below reconfigure steps:
1. Login to remote desktop >> open cmd prompt >> follow below reconfigure steps;
Basic Task
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Start Run
cmd
"%plesk_bin%\websrvmng.exe" --remove-sites-cache
"%plesk_bin%\websrvmng.exe" --reconfigure-vhost --vhost-name=domain-name.tld
Allow 2 r 3 mins to complete the task
After this remove your browser cache, cookies and try again.