SharePoint Error - HRESULT: 0x80131904

When my corporate team tries to  open a SharePoint publishing site, they get the following error message "HRESULT: 0x80131904 ".
It is generally due to Content DB SQL server error. The issue might be with the temp database or Content database size.
Their space is fully occupied. So kindly login into Content Database and make sure that you release more free space for SharePoint operations.
Hope it helps !