Why is the form asking to contain letters only?

BOM DIA , 

ESTOU TENTANDO REALIZAR O CADASTRO NO GADLE, E ESTÁ DANDO PROBLEMA PARA FINALIZAR O CADASTRO DEVIDO UM PROBLEMA NO SITE EM TODOS OS CAMPOS NUMERICOS '' This field can only contain letters and numbers. '' GOSTARIA DE REPORTAR ESSE PROBLEMA PARA QUE EU POSSA FINALIZAR O CADASTRO OBRIGADO .

GRATO 

This is not an error, the form fields have been configured to accept letters only and you will get this error if you're trying to add numbers or any other sort of symbol that's not a letter. 

Here's an example: 

If you're the form owner you will need to change the validation on the field settings, otherwise there is not much that we can do on this since it's a validation that the form's owner has imposed to the fields. 

Thanks.