As a safety precaution always go to your GOSSIP data directory and backup your wallet.dat, preferably on an offline location such as a secure flashdrive. Avoid online storage.

Now open your GOSSIP wallet, Select the TOOLS tab, select Wallet Repair in the drop down menu and lastly Select RESCAN BLOCKCHAIN FILES as seen in the image below

Your wallet should begin the rescan on the blockchain files for your missing transactions and your funds should show as normal. In some cases you may need to delete the old blockchain and completely resync everything.