I need help.

On 4/24, I bought 25000 USDe's on the poloniex exchange and tried to download them to my wallet.
I already had 75000 that I had bought and downloaded with no trouble weeks earlier. the 25000 has
never shown up and my wallet seems to be stuck on block 160899. I have upgraded to version 4 of
the wallet but this hasn't helped. I followed the same procedure I used last time so I don't know why
I would have trouble now. Any help or suggestions would be very much appreciated. I should add that
I have a mac system, if that makes a difference.

Thank you