Having the exact same problem with 7.5.3 - any help would be valuable.

In lack of a better workaround I hacked umbraco.controllers.js adding a try/catch so that it returns true in case of an error (not the best way, but at least it stopped throwing errors!).

 // Method required by the valPropertyValidator directive (returns true if the property editor has at least one tag selected)
            $scope.validateMandatory = function () {
                try {
                return {

                        isValid: !$scope.model.validation.mandatory || ($scope.model.value != null && $scope.model.value.length > 0),
                        errorMsg: "Value cannot be empty",
                        errorKey: "required"

                    };
                } catch (err) {
                    return { isValid: true, errorMsg: null, errorKey: null } }
            }

The problem is that autocomplete still doesn't seem to work.

This is still happening.

Umbraco version 7.12.1

Vorto 1.6.0

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