Need help! Shower enclosure leaking. (Not a plumbing issue.)

I had the same thing. Took it apart completly. Got a roll of sealant from local glass store. About 1 3/4 wide put down on base and verticals and reassembled. I used Polyseamseal on all the alum extrusions after it was put back together. It is water solubal unlike silicone so you can really do a nice job. When dry it is like silicon but should not be used where water could stand. Mine leaked from day one. Sloppy workers. Did you watch them making RV'S on PBS? They have no TIME to do it right.