Ok reindex fails with `fatal error occurred`, this is the log but I think LoyceV  may well be correct...
Thanks for the feedback, I have dat files safe

best=00000000000000000e7f7840597bd01793617a08281f95128b0591fc358c5b99 height=316097 version=0x00000002 log2_work=80.231896 tx=44754159 date='2014-08-17T15:16:57Z' progress=0.125087 cache=575.9MiB(4206868txo)
2018-12-04T12:34:09Z Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).


2018-12-04T12:34:09Z You can use -debug=leveldb to get more complete diagnostic messages
2018-12-04T12:34:09Z *** System error while flushing: Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).


2018-12-04T15:35:47Z UPnP Port Mapping successful.
2018-12-04T15:36:35Z Failed to connect best block (System error while flushing: Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).

 (code 0))
2018-12-04T15:36:35Z socket sending timeout: 10963s
2018-12-04T15:36:35Z Potential stale tip detected, will try using extra outbound peer (last tip update: 10947 seconds ago)
2018-12-04T15:36:35Z socket sending timeout: 10947s
2018-12-04T15:36:35Z socket receive timeout: 10854s
2018-12-04T15:36:35Z tor: Thread interrupt
2018-12-04T15:36:35Z addcon thread exit
2018-12-04T15:36:35Z msghand thread exit
2018-12-04T15:36:35Z net thread exit
2018-12-04T15:36:35Z Shutdown: In progress...
2018-12-04T15:36:35Z torcontrol thread exit
2018-12-04T15:36:35Z opencon thread exit
2018-12-04T15:36:36Z UPNP_DeletePortMapping() returned: 0
2018-12-04T15:36:36Z upnp thread exit
2018-12-04T15:36:37Z [default wallet] AddToWallet 2d62f39b1cce947763657af22559f07f348b53d853fe4706ec1240b1567124f2 
2018-12-04T15:36:38Z scheduler thread interrupt
2018-12-04T15:36:38Z Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).

2018-12-04T15:36:38Z You can use -debug=leveldb to get more complete diagnostic messages
2018-12-04T15:36:38Z *** System error while flushing: Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).

2018-12-04T15:36:42Z FlushStateToDisk: failed to flush state (System error while flushing: Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).

 (code 0))
2018-12-04T15:36:42Z Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).

2018-12-04T15:36:42Z You can use -debug=leveldb to get more complete diagnostic messages
2018-12-04T15:36:42Z *** System error while flushing: Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).

2018-12-04T15:36:43Z FlushStateToDisk: failed to flush state (System error while flushing: Fatal LevelDB error: IO error: F:\Bitcoin\Bitcoin1\chainstate\001736.ldb: Data error (cyclic redundancy check).

 (code 0))
2018-12-04T15:36:46Z [default wallet] Releasing wallet
2018-12-04T15:36:46Z Shutdown: done