Why doesn't the minmax character validation work in the vee-validate library?

Question

Vue.js

I add the following validation setting to main.ls
extend('minmax', {
validate(value, { min, max }) {
return value. length >= min && value. length <= max;
},
params: ['min', 'max'],
message: 'The field must be at least {min} characters and at most {max} characters'
});
Validation works, but an error is written to the console.
main.js:2 Uncaught (in promise) TypeError: Cannot read property 'length' of undefined

How to overcome this problem?