It looks like you are trying to use Java 8’s Instant type with Spring Boot 2.5.0, but it is not supported by default.

To resolve this issue, you can try adding the following dependency to your project:

<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jsr310</artifactId>
</dependency>

This dependency will allow Spring Boot to properly serialize and deserialize the Instant type. You may also need to configure your application to use the JavaTimeModule from the jackson-datatype-jsr310 library by adding the following line to your application’s configuration:

objectMapper.registerModule(new JavaTimeModule());

This will allow Spring Boot to properly handle the Instant type when serializing and deserializing JSON.

Note that if you are using Spring Boot 2.3.0 or later, you don’t need to add the jackson-datatype-jsr310 dependency as it is already included in the default dependency management. However, you may still need to configure your application to use the JavaTimeModule.