Error showing when try to override discount on pos. error showing

"The maximum discount percentage line allowed is: 5%, Please enter a smaller percentage". 

The message is a validation based on the configuration.

In retail profile , "Max Line Discount Percent Allowed" value field need to be checked for such validation messages.

In the presented case the value was set to  5 % ( i.e. showing in error).but user is trying to override discount as 10%.

Either customer need to follow the validation or if the higher discount is to be applied then need to update Max Line Discount Percent Allowed value in retail profile, as per requirement