The status of SIMP wallet:
Sync.
Uploaded 8436 blocks of transaction history.
Last received block was generated 1 hour ago.
0 active connections to the network.
I also had this problem but I restarted my pc and run the wallet and opened it up again twice. The second time it worked after waiting some time. I just left the pc to do its thing and when I came back it was fine. 13 active connections ^^