Reported here: https://github.com/bitcoin/bitcoin/pull/10244#issuecomment-378035305

Travis log here: https://travis-ci.org/bitcoin/bitcoin/jobs/361243719#L2810

Note the JSON exception:

```
test_framework.authproxy.JSONRPCException: The mempool was not loaded yet (-1) 
```

That exception was introduced here: https://github.com/bitcoin/bitcoin/commit/cb1e319fe9e198c9c5cf5236fe9af5a3d748b9e8#diff-a0c8f511d90e83aa9b5857e819ced344R1617

cc @jtimon 
break;
                    }
                }
                if (!is_coinsview_empty) {
                    uiInterface.InitMessage(_("Verifying blocks..."));
                    if (fHavePruned && gArgs.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS) > MIN_BLOCKS_TO_KEEP) {
                        LogPrintf("Prune: pruned datadir may not have more than %d blocks; only checking available blocks\n",
                            MIN_BLOCKS_TO_KEEP);
                    }
                    CBlockIndex* tip = chainActive.Tip();
                    RPCNotifyBlockChange(true, tip);
                    if (tip && tip->nTime > GetAdjustedTime() + 2 * 60 * 60) {
                        strLoadError = _("The block database contains a block which appears to be from the future. "
                                "This may be due to your computer's date and time being set incorrectly. "
                                "Only rebuild the block database if you are sure that your computer's date and time are correct");
                        break;
                    }
                    if (!CVerifyDB().VerifyDB(chainparams, pcoinsdbview.get(), gArgs.GetArg("-checklevel", DEFAULT_CHECKLEVEL),
                                  gArgs.GetArg("-checkblocks", DEFAULT_CHECKBLOCKS))) {
                        strLoadError = _("Corrupted block database detected");
                        break;
                    }
                }
            } catch (const std::exception& e) {
                LogPrintf("%s\n", e.what());
                strLoadError = _("Error opening block database");
                break;
            }
            fLoaded = true;
            LogPrintf(" block index %15dms\n", GetTimeMillis() - load_block_index_start_time);