When selecting a user library as the JPA implementation in Eclipse Dali's project settings, the following error message is displayed:

> 
> The class 'javax.persistence.Convert' is required to be in the selected libraries
> 
> 
> 

[![enter image description here](https://i.stack.imgur.com/pJWrL.jpg)](https://i.stack.imgur.com/pJWrL.jpg)

But the class `javax.persistence.Convert` is correctly included in the classpath of my user library, so how can this problem be resolved?