Considering these two sentences in the past tense, using "never":
The film has never been released
The film was never released
Are they both correct? If so, is there a difference in the meaning, or usage?
The first, using the present perfect construction, relates the non-release of the film to the time of speaking or writing. It might continue with the words ‘up until now’. The second, using the past tense, places the non-release at some specific period or time in the past.
That said, the meaning depends very much on the context. For example, the second sentence might continue ‘during his lifetime’, and there might then be another sentence saying ‘But there are now plans to make it available to the public.’
They are both correct, and both can be used interchangeably.
The only difference I would read into it is that "was never" means the project is dead and it will never happen. Saying "has never been" implies, to my ear, that there's a chance it may happen someday.
In nearly any case, I'd say the difference is irrelevant.