Quando clico em enviar, a oferta vai pro banco de dados, mas aparece o seguinte erro : (COMPLETO)

jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:166) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.11.0.jar:2.11.0] at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:723) ~[jackson-databind-2.11.0.jar:2.11.0]