Debug info:(0)
<p><code>Unknown database 'dbmasteruser'</code></p>
<h1>Cannot select database</h1>
<p>The database server could be connected to (which means your username and password is okay) but the <code>dbmasteruser</code> database could not be selected.</p>
<ul>
<li>Are you sure it exists?</li>
<li>Does the user <code>dbmasteruser</code> have permission to use the <code>dbmasteruser</code> database?</li>
<li>On some systems the name of your database is prefixed with your username, so it would be like <code>username_dbmasteruser</code>. Could that be the problem?</li>
</ul>
<p>If you do not know how to set up a database you should <strong>contact your host</strong>. If all else fails you may find help at the <a href="https://wordpress.org/support/forums/">GetHelpIsrael support forums</a>.</p>