Which wallet are you using? Have you tried the Wallet v1.2.8
Check to see if it's your antivirus is removing the wallet program. Some throw false positives and, in my case, remove the wallet program from the PC.
I'm sure you already did, but ensure that your wallet has received burst. It also needs an outgoing transaction. So, you can change the name of your wallet or send out one Burst to another wallet (faucet).
If you program in Java, you're worth more than gold here. Welcome :)