Why would they delete it?
Do you still have the old wallet app, as it will not sync with the new blockchain due to a copule of forks (there was one at 0.8.5 fore example that will make it impossible for your old version of bitcoin core to sync).
Does your wallet folder have a debug.log in it, could you post that in its entirety?

Finding the debug.log file:
1. If your folder with your bitcoin app has a blocks and chainstate folder then your debug.log will be in the same directory as your bitcoin wallet.
2. If not, go to C:\users\\appdata\local\bitcoin or c:\users\\appdata\roaming\bitcoin and the debug.log should be in one of these.