Poulan Pro pp175g42 not moving

[Odyssey64]

I put my poulan pro in reverse after starting it and it backed away from my shed. But when I put it in third gear it wouldn't move. I tried putting it back in reverse but this time it wouldn't move in reverse either. I tried putting it into each gear up to six and nothing. The engine starts fine, the brake seems to work also. The deck lowers and the blades engage with no issue. I don't get it, it initially moved in reverse but now won't go forward. Any immediate help would be greatly appreciated because I have a backyard gathering coming up this weekend and need to get the lawn done.

 

[bertsmobile1]

Have a look under the mower
The transmission belt has probably jumped off the drive pulley
Go to Parts tree- Jacks Small Engines etc and find your mowers parts lists
Have a close look at the transmission &/or frame sections to find the transmission support / anti-roll brackets
Better than average chance they are loose or fallen off