I had that problem on TestNet, you have to delete the chain in the .zcash folder then re-index
Reindex not working on RC4 and mainnet! (stuck on 145 block) On start I tried launch zcashd 20+ times before get success. Now I hold two separate instances of zcash blockchain for "hotplugging" on zcashd crash, but it can't save from wallet corrupting. I already have one 4Mb corrupted wallet.dat... -salvagewallet don't work, I emailed zcash dev team, may be they can help me repair this wallet.dat, but don't receive answer until this moment. I think it's not good start for zcash.