Please make sure that you have taken following steps correctly:
- If you are accessing your install using domain name make sure that your website is pointing to correct server.
- If there is any contents, remove installation from Softaculous and remove other contents from the same directory and attempt to install again.
- Make sure that you are accessing the URL correctly. If you have installed in subfolder, subdomain, you will have to use the exact URL.
If it still does not work, you will have to contact your web hosting provider.
User1984 commented on answer