Another Problem Installing Beta 2

Hi Guys ,

Finally I was able to get through to the Installing screen but once I click Install flarum I get this error :

Something went wrong: validation.alpha_dash

Though all the inputs are right and I didn't input any capital letter or dots or special characters

That's an old problem and wouldn't occur with Beta 4 😉

Thanks 🙂 Is there any solution for it ? since I cant Install beta 4 🙁