If you came across this error while installing any application from Softaculous after clicking on the install Button then don’t panic you can apply the below simple fix to get rid of that error :
Login to WHM >> Main >> SQL Services >> MySQL Root Password
and then reset the mysql root password and now try to installing any application from Softaculous Panel it will no longer show any error.
And if you still face the same error then make sure that you have not disabled the Database Prefix in WHM .
You can refer the below URL to re-enable the database prefix if you mistakenly disabled the database prefix in WHM.