ClassNotFoundException: org.springframework.data.redis.core.RedisTemplate

The ClassNotFoundException: org.springframework.data.redis.core.RedisTemplate error occurs when the required RedisTemplate class from the Spring Data Redis library is not found. This can happen due to several reasons:

1. Missing dependency: If the Spring Data Redis library is not added to the project's dependencies, then the RedisTemplate class will not be found.

2. Incorrect version: If the version of the Spring Data Redis library used in the project is incompatible with the RedisTemplate class, then it will not be found.

3. Classpath issue: If the RedisTemplate class is not present in the classpath of the application, then it will not be found.

To fix this error, ensure that the Spring Data Redis library is added as a dependency in the project's build file, and that the correct version is used. Also, ensure that the RedisTemplate class is present in the classpath of the application.