Customise standard validation error messages in approval process submission
   When a record is submitted for approval from items to approve section/ or through a custom button from visualforce page, if there are any validation errors, Salesforce redirects the user to a new page as shown in below screenshot:        You can customise the error message in trigger using addError() method.      Account acctObj = Trigger.new[0];    String errorMessage = 'Click here to go to Account, <a href="https://www.blogger.com/'+URL.getSalesforceBaseUrl().toExternalForm()+'/'+acctObj.Id+'">here</a>';    acctObj.addError('<b><span style="color: red;">'+errorBody+'</span></b>');