As a long time d&d player I can tell you, every d&d based movie was a disappointment.

I expect this series to be the same.

The reason is quite simple, out of all the best selling scenarios created for d&d over the decades, be it in game form or novel form, it never occurred to them to adapt a single one. They always use a cookie cutter scenario that appeals to no one but the movie execs that know nothing about d&d.

Nothing will work until they figure that out.

You want a worthwhile movie franchise from d&d? Look no further than Dragonlance Chronicles. Attach a fan as project leader (like Peter Jackson was for LotR) and you are golden.