ERROR('') results in NavNCLDialogException

Hi,

NAV2017 - CU2.1

I have a function in a codeunit that subscribes to an event in a table.
If certain checks fail, I want to rollback silently with ERROR('') - don't want to just EXIT.

However, it results in the following:

Exception of type 'Microsoft.Dynamics.Nav.Types.Exceptions.NavNCLDialogException' was thrown.

Initially I thought it has to do with error handling from subscribers.
But I replaced the code in the table that calls the event publishing function with ERROR('') - same result..

Are there cases where you can't use ERROR('') that I'm not aware of?

Kind Regards,

EV